Form N-Q

UNITED STATES
SECURITIES AND EXCHANGE COMMISSION
Washington, DC 20549

FORM N-Q


QUARTERLY SCHEDULE OF PORTFOLIO HOLDINGS OF REGISTERED MANAGEMENT INVESTMENT COMPANY

Investment Company Act file number         811-10197         

        Nuveen California Dividend Advantage Municipal Fund 2         
(Exact name of registrant as specified in charter)


        333 West Wacker Drive, Chicago, Illinois 60606         
(Address of principal executive offices) (Zip code)


Jessica R. Droeger—Vice President and Secretary
        333 West Wacker Drive, Chicago, Illinois 60606         
(Name and address of agent for service)

Registrant's telephone number, including area code:         312-917-7700        

Date of fiscal year end:            8/31          

Date of reporting period:          5/31/06         

Form N-Q is to be used by management investment companies, other than small business investment companies registered on Form N-5 (§§ 239.24 and 274.5 of this chapter), to file reports with the Commission, not later than 60 days after the close of the first and third fiscal quarters, pursuant to rule 30b1-5 under the Investment Company Act of 1940 (17 CFR 270.30b1-5). The Commission may use the information provided on Form N-Q in its regulatory, disclosure review, inspection, and policymaking roles.

A registrant is required to disclose the information specified by Form N-Q, and the Commission will make this information public. A registrant is not required to respond to the collection of information contained in Form N-Q unless the Form displays a currently valid Office of Management and Budget (“OMB”) control number. Please direct comments concerning the accuracy of the information collection burden estimate and any suggestions for reducing the burden to the Secretary, Securities and Exchange Commission, 450 Fifth Street, NW, Washington, DC 20549-0609. The OMB has reviewed this collection of information under the clearance requirements of 44 U.S.C. § 3507.

Item 1. Schedule of Investments

                           Portfolio of Investments (Unaudited)             
                           Nuveen California Dividend Advantage Municipal Fund 2 (NVX)             
                           May 31, 2006             
        Optional         
Principal        Call         
Amount (000)    Description (1)    Provisions (2)    Ratings (3)    Value 
    Consumer Staples – 4.0% (2.7% of Total Investments)             
$             825    California County Tobacco Securitization Agency, Tobacco Settlement Asset-Backed Bonds, Sonoma    6/15 at 100.00    BBB   $   797,866 
     County Tobacco Securitization Corporation, Series 2005, 4.250%, 6/01/21             
4,625    California County Tobacco Securitization Agency, Tobacco Settlement Asset-Backed Bonds,    6/12 at 100.00    Baa3    4,706,446 
     Stanislaus County Tobacco Funding Corporation, Series 2002A, 5.500%, 6/01/33             
3,200    Golden State Tobacco Securitization Corporation, California, Tobacco Settlement Asset-Backed    6/13 at 100.00    BBB    3,466,208 
     Bonds, Series 2003A-1, 6.250%, 6/01/33             
8,650    Total Consumer Staples            8,970,520 
     Education and Civic Organizations – 15.5% (10.3% of Total Investments)             
2,000    California Educational Facilities Authority, Revenue Bonds, Stanford University, Series 2001Q,    6/11 at 101.00    AAA    2,093,840 
     5.250%, 12/01/32             
180    California Educational Facilities Authority, Revenue Bonds, University of Redlands, Series    10/15 at 100.00    A3    181,121 
     2005A, 5.000%, 10/01/35             
    California Educational Facilities Authority, Revenue Bonds, University of the Pacific,             
    Series 2006:             
125     5.000%, 11/01/21 (WI/DD, Settling 6/01/06)    11/15 at 100.00    A2    129,216 
165     5.000%, 11/01/25 (WI/DD, Settling 6/01/06)    11/15 at 100.00    A2    169,420 
6,375    California Educational Facilities Authority, Student Loan Revenue Bonds, Cal Loan Program,    3/08 at 102.00    Aaa    6,587,351 
     Series 2001A, 5.400%, 3/01/21 – MBIA Insured (Alternative Minimum Tax)             
    California State Public Works Board, Lease Revenue Bonds, University of California, UCLA             
    Replacement Hospital Project, Series 2002A:             
8,880     5.375%, 10/01/16 – FSA Insured    10/12 at 100.00    AAA    9,586,049 
10,570     5.375%, 10/01/18 – FSA Insured    10/12 at 100.00    AAA    11,366,238 
570    California State University, Systemwide Revenue Bonds, Series 2005A, 5.000%, 11/01/30 –    5/15 at 100.00    AAA    589,243 
     AMBAC Insured             
620    California Statewide Community Development Authority, Revenue Bonds, Notre Dame de Namur    10/13 at 100.00    N/R    659,829 
     University, Series 2003, 6.500%, 10/01/23             
3,000    Long Beach Bond Financing Authority, California, Lease Revenue Refunding Bonds, Long Beach    11/11 at 101.00    AAA    3,136,830 
     Aquarium of the South Pacific, Series 2001, 5.250%, 11/01/30 – AMBAC Insured             
32,485    Total Education and Civic Organizations            34,499,137 
    Health Care – 11.8% (7.9% of Total Investments)             
2,000    California Health Facilities Financing Authority, Revenue Bonds, Casa Colina Inc., Series    4/12 at 100.00    BBB+    2,116,540 
     2001, 6.000%, 4/01/22             
1,240    California Health Facilities Financing Authority, Revenue Bonds, Cedars-Sinai Medical Center,    11/15 at 100.00    A3    1,251,693 
     Series 2005, 5.000%, 11/15/34             
500    California Infrastructure Economic Development Bank, Revenue Bonds, Kaiser Hospital Assistance    8/11 at 102.00    A+    523,590 
     LLC, Series 2001A, 5.550%, 8/01/31             
955    California State Public Works Board, Revenue Bonds, University of California – Davis Medical    11/14 at 100.00    AAA    989,132 
     Center, Series 2004II-A, 5.000%, 11/01/22 – MBIA Insured             
2,185    California Statewide Community Development Authority, Health Facility Revenue Refunding Bonds,    No Opt. Call    A+    2,385,539 
     Memorial Health Services, Series 2003A, 6.000%, 10/01/11             
2,500    California Statewide Community Development Authority, Hospital Revenue Bonds, Monterey    6/13 at 100.00    AAA    2,650,775 
     Peninsula Hospital, Series 2003B, 5.250%, 6/01/18 – FSA Insured             
    California Statewide Community Development Authority, Revenue Bonds, Daughters of Charity             
    Health System, Series 2005A:             
330     5.250%, 7/01/24    7/15 at 100.00    BBB+    338,857 
190     5.250%, 7/01/35    7/15 at 100.00    BBB+    193,982 
5,775    California Statewide Community Development Authority, Revenue Bonds, Kaiser Permanante System,    3/16 at 100.00    A+    5,801,103 
     Series 2006, 5.000%, 3/01/41 (WI/DD, Settling 6/08/06)             
5,355    California Statewide Community Development Authority, Revenue Bonds, Kaiser Permanente System,    No Opt. Call    A+    5,442,876 
     Series 2002E, 4.700%, 11/01/36 (Mandatory put 6/01/09)             
3,000    Central California Joint Powers Health Finance Authority, Certificates of Participation,    2/10 at 101.00    Baa2    3,113,430 
     Community Hospitals of Central California Obligated Group, Series 2000, 6.000%, 2/01/30             
1,500    Whittier, California, Health Facility Revenue Bonds, Presbyterian Intercommunity Hospital,    6/12 at 101.00    A    1,578,405 
     Series 2002, 5.600%, 6/01/22             
25,530    Total Health Care            26,385,922 
    Housing/Multifamily – 11.6% (7.7% of Total Investments)             
2,450    ABAG Finance Authority for Non-Profit Corporations, California, Multifamily Housing Revenue    No Opt. Call    BBB    2,538,617 
     Refunding Bonds, United Dominion/2000 Post Apartments, Series 2000B, 6.250%, 8/15/30             
     (Mandatory put 8/15/08)             
3,460    California Statewide Community Development Authority, GNMA Collateralized Housing Revenue    8/12 at 105.00    Aaa    3,820,186 
     Refunding Bonds, Crowne Pointe Project, Series 2002F, 6.750%, 8/20/37             
5,962    California Statewide Community Development Authority, Multifamily Housing Revenue Refunding    6/11 at 102.00    AAA    6,365,806 
     Bonds, Claremont Village Apartments, Series 2001D, 5.500%, 6/01/31 (Mandatory put 6/01/16)             
     (Alternative Minimum Tax)             
3,250    California Statewide Community Development Authority, Revenue Refunding Bonds, Irvine    7/08 at 101.00    BBB    3,281,882 
     Apartment Communities Development, Series 1998A, 4.900%, 5/15/25 (Mandatory put 5/15/08)             
4,000    Daly City Housing Development Finance Agency, California, Mobile Home Park Revenue Bonds,    12/13 at 102.00    A–    4,370,840 
     Franciscan Mobile Home Park Project, Series 2002A, 5.850%, 12/15/32             
205    Independent Cities Lease Finance Authority, California, Mobile Home Park Revenue Bonds, San    5/16 at 100.00    N/R    206,207 
     Juan Mobile Estates Project, Series 2006A, 5.850%, 5/15/41 (WI/DD, Settling 6/01/06)             
1,055    Rohnert Park Finance Authority, California, Senior Lien Revenue Bonds, Rancho Feliz Mobile    9/13 at 100.00    A–    1,137,796 
     Home Park, Series 2003A, 5.750%, 9/15/38             
700    Rohnert Park Finance Authority, California, Subordinate Lien Revenue Bonds, Rancho Feliz    9/13 at 100.00    N/R    748,643 
     Mobile Home Park, Series 2003B, 6.625%, 9/15/38             
3,045    Yucaipa Redevelopment Agency, California, Mobile Home Park Revenue Bonds, Rancho del Sol and    5/11 at 102.00    N/R    3,395,784 
     Grandview, Series 2001A, 6.750%, 5/15/36             
24,127    Total Housing/Multifamily            25,865,761 
    Housing/Single Family – 0.4% (0.2% of Total Investments)             
710    California Rural Home Mortgage Finance Authority, Mortgage-Backed Securities Program Single    6/11 at 102.00    AAA    721,637 
     Family Mortgage Revenue Bonds, Series 2001A, 5.650%, 12/01/31 (Alternative Minimum Tax)             
    Industrials – 0.6% (0.4% of Total Investments)             
1,250    California Pollution Control Financing Authority, Solid Waste Disposal Revenue Bonds, Waste    1/16 at 102.00    BBB    1,259,800 
     Management Inc., Series 2002A, 5.000%, 1/01/22 (Alternative Minimum Tax)             
    Long-Term Care – 0.7% (0.5% of Total Investments)             
1,550    California Health Facilities Financing Authority, Cal-Mortgage Insured Revenue Bonds, Northern    1/13 at 100.00    A    1,591,726 
     California Retired Officers Community Corporation – Paradise Valley Estates, Series 2002,             
     5.125%, 1/01/22             
    Tax Obligation/General – 22.9% (15.2% of Total Investments)             
    California, General Obligation Bonds, Series 2003:             
3,000     5.250%, 2/01/20    8/13 at 100.00    A    3,169,260 
1,400     5.250%, 2/01/21    8/13 at 100.00    A    1,478,988 
    California, General Obligation Bonds, Series 2004:             
1,350     5.125%, 4/01/25    4/14 at 100.00    A    1,401,030 
1,000     5.125%, 2/01/27    2/14 at 100.00    A    1,034,510 
5,000    California, General Obligation Refunding Bonds, Series 2002, 5.000%, 2/01/12    No Opt. Call    A    5,284,750 
4,225    California, General Obligation Veterans Welfare Bonds, Series 2001BV, 5.600%, 12/01/32 –    6/06 at 101.00    AAA    4,273,038 
     FSA Insured             
3,615    Colton Joint Unified School District, San Bernardino County, California, General Obligation    8/12 at 102.00    AAA    3,948,737 
     Bonds, Series 2002A, 5.500%, 8/01/22 – FGIC Insured             
    Contra Costa County Community College District, California, General Obligation Bonds,             
    Series 2002:             
3,005     5.000%, 8/01/21 – FGIC Insured    8/12 at 100.00    AAA    3,121,654 
3,300     5.000%, 8/01/22 – FGIC Insured    8/12 at 100.00    AAA    3,433,749 
1,325    Golden West Schools Financing Authority, California, General Obligation Revenue Refunding    No Opt. Call    AAA    1,555,338 
     Bonds, School District Program, Series 1998A, 6.650%, 8/01/13 – MBIA Insured             
10,840    Los Angeles Unified School District, California, General Obligation Bonds, Series 2002E,    7/12 at 100.00    AAA    11,385,794 
     5.000%, 7/01/19 – MBIA Insured             
1,250    Los Angeles Unified School District, California, General Obligation Bonds, Series 2003A,    7/13 at 100.00    AAA    1,336,838 
     5.250%, 7/01/20 – FSA Insured             
    Oakland Unified School District, Alameda County, California, General Obligation Bonds,             
    Series 2005:             
475     5.000%, 8/01/25 – MBIA Insured    8/15 at 100.00    AAA    493,915 
500     5.000%, 8/01/26 – MBIA Insured    8/15 at 100.00    AAA    518,770 
2,000    Puerto Rico, General Obligation and Public Improvement Bonds, Series 2001A, 5.500%, 7/01/20 –    No Opt. Call    AAA    2,243,600 
     MBIA Insured             
    San Jose-Evergreen Community College District, Santa Clara County, California, General             
    Obligation Bonds, Series 2005A:             
370     5.000%, 9/01/25 – MBIA Insured    9/15 at 100.00    AAA    385,980 
545     5.000%, 9/01/27 – MBIA Insured    9/15 at 100.00    AAA    566,021 
4,050    Santa Rosa High School District, Sonoma County, California, General Obligation Bonds, Series    5/11 at 101.00    AAA    4,286,317 
     2001, 5.300%, 5/01/26 – FGIC Insured             
1,160    Saugus Union School District, Los Angeles County, California, General Obligation Bonds, Series    8/12 at 100.00    AAA    1,205,031 
     2002A, 5.000%, 8/01/21 – FGIC Insured             
48,410    Total Tax Obligation/General            51,123,320 
    Tax Obligation/Limited – 28.2% (18.8% of Total Investments)             
    Beaumont Financing Authority, California, Local Agency Revenue Bonds, Series 2004D:             
650     5.500%, 9/01/24    9/14 at 102.00    N/R    675,500 
385     5.800%, 9/01/35    9/14 at 102.00    N/R    403,295 
4,900    California State Public Works Board, Lease Revenue Bonds, Department of Corrections, Series    12/13 at 100.00    A–    5,298,664 
     2003C, 5.500%, 6/01/16             
2,105    California, Economic Recovery Revenue Bonds, Series 2004A, 5.000%, 7/01/15    7/14 at 100.00    AA–    2,243,846 
1,200    Capistrano Unified School District, Orange County, California, Special Tax Bonds, Community    9/13 at 100.00    N/R    1,262,808 
     Facilities District 90-2 – Talega, Series 2003, 6.000%, 9/01/33             
4,845    Encinitas Public Financing Authority, California, Lease Revenue Bonds, Acquisition Project,    4/08 at 102.00    AAA    5,041,755 
     Series 2001A, 5.250%, 4/01/31 – MBIA Insured             
750    Fontana, California, Special Tax Bonds, Sierra Community Facilities District 22, Series 2004,    9/14 at 100.00    N/R    790,538 
     6.000%, 9/01/34             
335    Hesperia Community Redevelopment Agency, California, Tax Allocation Bonds, Series 2005A,    9/15 at 100.00    AAA    350,246 
     5.000%, 9/01/20 – XLCA Insured             
4,000    Industry Urban Development Agency, California, Tax Allocation Refunding Bonds, Civic,    5/07 at 101.50    AAA    4,122,000 
     Recreational and Industrial Redevelopment Project 1, Series 2002, 5.500%, 5/01/19 –             
     MBIA Insured             
    Irvine, California, Unified School District, Community Facilities District Special Tax Bonds,             
    Series 2006A:             
215     5.000%, 9/01/26    9/06 at 103.00    N/R    216,269 
495     5.125%, 9/01/36    9/06 at 103.00    N/R    495,153 
2,000    Lake Elsinore Public Finance Authority, California, Local Agency Revenue Refunding Bonds,    10/13 at 102.00    N/R    2,165,280 
     Series 2003H, 6.000%, 10/01/20             
1,265    Lee Lake Water District, Riverside County, California, Special Tax Bonds, Community Facilities    9/13 at 102.00    N/R    1,397,989 
     District 1 of Sycamore Creek, Series 2003, 6.500%, 9/01/24             
1,320    Lincoln, California, Special Tax Bonds, Lincoln Crossing Community Facilities District 03-1,    9/13 at 102.00    N/R    1,453,676 
     Series 2003A, 6.500%, 9/01/25             
1,000    Lincoln, California, Special Tax Bonds, Lincoln Crossing Community Facilities District 03-1,    9/13 at 102.00    N/R    1,059,190 
     Series 2004, 6.000%, 9/01/34             
8,000    Los Angeles County Metropolitan Transportation Authority, California, Proposition C Second    7/08 at 101.00    AAA    8,236,640 
     Senior Lien Sales Tax Revenue Refunding Bonds, Series 1998A, 5.000%, 7/01/23 – AMBAC Insured             
5,000    Los Angeles County Metropolitan Transportation Authority, California, Proposition C Second    No Opt. Call    AAA    5,448,000 
     Senior Lien Sales Tax Revenue Refunding Bonds, Series 2003A, 5.250%, 7/01/13 – MBIA Insured             
3,295    Oakland Redevelopment Agency, California, Subordinate Lien Tax Allocation Bonds, Central    3/13 at 100.00    AAA    3,597,250 
     District Redevelopment Project, Series 2003, 5.500%, 9/01/16 – FGIC Insured             
2,000    Orange County, California, Special Tax Bonds, Community Facilities District 02-1 of Ladera    8/11 at 101.00    N/R    2,042,820 
     Ranch, Series 2003A, 5.550%, 8/15/33             
2,000    Puerto Rico Public Finance Corporation, Commonwealth Appropriation Bonds, Series 2002E,    No Opt. Call    BBB–    2,292,240 
     6.000%, 8/01/26             
385    Rialto Redevelopment Agency, California, Tax Allocation Bonds, Merged Project Area, Series    9/15 at 100.00    AAA    393,701 
     2005A, 5.000%, 9/01/35 – XLCA Insured             
800    Riverside County Public Financing Authority, California, Tax Allocation Bonds, Multiple    10/15 at 100.00    AAA    818,216 
     Projects, Series 2005A, 5.000%, 10/01/35 – XLCA Insured             
6,000    Riverside County Redevelopment Agency, California, Tax Allocation Bonds, Jurupa Valley Project    10/11 at 102.00    AAA    6,279,960 
     Area, Series 2001, 5.250%, 10/01/35 – AMBAC Insured             
700    Sacramento, California, Special Tax Bonds, North Natomas Community Facilities District 4,    9/14 at 100.00    N/R    743,141 
     Series 2003C, 6.000%, 9/01/33             
975    San Marcos Public Facilities Authority, California, Special Tax Bonds, Community Facilities    9/09 at 102.00    N/R    1,017,842 
     District 99-1, Series 2003B, 6.000%, 9/01/24             
1,530    San Marcos Public Facilities Authority, California, Tax Allocation Bonds, Project Areas 2 and    8/15 at 100.00    AAA    1,570,071 
     3, Series 2005C, 5.000%, 8/01/35 – AMBAC Insured             
1,930    West Patterson Financing Authority, California, Special Tax Bonds, Community Facilities    9/13 at 103.00    N/R    2,135,313 
     District 01-1, Series 2003B, 6.750%, 9/01/30             
500    West Patterson Financing Authority, California, Special Tax Bonds, Community Facilities    9/13 at 102.00    N/R    530,730 
     District 01-1, Series 2004B, 6.000%, 9/01/39             
850    West Patterson Financing Authority, California, Special Tax Bonds, Community Facilities    9/13 at 103.00    N/R    912,484 
     District 2001-1, Series 2004A, 6.125%, 9/01/39             
59,430    Total Tax Obligation/Limited            62,994,617 
    Transportation – 10.0% (6.6% of Total Investments)             
1,930    Bay Area Toll Authority, California, Revenue Bonds, San Francisco Bay Area Toll Bridge, Series    4/16 at 100.00    AA    1,995,794 
     2006, 5.000%, 4/01/31             
7,000    Foothill/Eastern Transportation Corridor Agency, California, Toll Road Revenue Refunding    1/14 at 101.00    BBB–    6,114,710 
     Bonds, Series 1999, 0.000%, 1/15/27             
5,585    Port of Oakland, California, Revenue Bonds, Series 2002N, 5.000%, 11/01/16 – MBIA Insured    11/12 at 100.00    AAA    5,806,780 
     (Alternative Minimum Tax)             
    San Francisco Airports Commission, California, Revenue Bonds, San Francisco International             
    Airport, Second Series 2003, Issue 29A:             
2,430     5.250%, 5/01/18 – FGIC Insured (Alternative Minimum Tax)    5/13 at 100.00    AAA    2,548,244 
2,555     5.250%, 5/01/19 – FGIC Insured (Alternative Minimum Tax)    5/13 at 100.00    AAA    2,673,118 
1,000    San Francisco Airports Commission, California, Revenue Bonds, San Francisco International    5/13 at 100.00    AAA    1,052,660 
     Airport, Second Series 2003, Issue 29B, 5.125%, 5/01/17 – FGIC Insured             
2,000    San Francisco Airports Commission, California, Revenue Refunding Bonds, San Francisco    5/12 at 100.00    AAA    2,089,220 
     International Airport, Second Series 2002, Issue 28A, 5.250%, 5/01/17 – MBIA Insured             
     (Alternative Minimum Tax)             
22,500    Total Transportation            22,280,526 
    U.S. Guaranteed – 25.8% (17.2% of Total Investments) (4)             
9,000    Anitoch Area Public Facilities Financing Agency, California, Special Tax Bonds, Community    8/11 at 100.00    AAA    9,664,110 
     Facilities District 1989-1, Series 2001, 5.250%, 8/01/25 (Pre-refunded 8/01/11) – MBIA Insured             
6,000    California Department of Water Resources, Power Supply Revenue Bonds, Series 2002A, 5.125%,    5/12 at 101.00    Aaa    6,489,420 
     5/01/18 (Pre-refunded 5/01/12)             
7,530    Los Angeles Unified School District, California, General Obligation Bonds, Series 2000D,    7/10 at 100.00    AAA    8,025,775 
     5.375%, 7/01/25 (Pre-refunded 7/01/10) – FGIC Insured             
1,375    Lucia Mar Unified School District, San Luis Obispo County, California, General Obligation    8/14 at 100.00    Aaa    1,503,178 
     Bonds, Series 2004A, 5.250%, 8/01/21 (Pre-refunded 8/01/14) – FGIC Insured             
3,000    Northern California Tobacco Securitization Authority, Tobacco Settlement Asset-Backed Bonds,    6/11 at 100.00    Aaa    3,225,780 
     Series 2001A, 5.375%, 6/01/41 (Pre-refunded 6/01/11)             
15,090    Santa Clara Valley Transportation Authority, California, Sales Tax Revenue Bonds, Series    6/11 at 100.00    AAA    16,004,906 
     2001A, 5.000%, 6/01/25 (Pre-refunded 6/01/11) – MBIA Insured             
6,200    Southwestern Community College District, San Diego County, California, General Obligation    8/11 at 101.00    AAA    6,745,042 
     Bonds, Series 2001, 5.375%, 8/01/25 (Pre-refunded 8/01/11) – AMBAC Insured             
2,710    Southwestern Community College District, San Diego County, California, General Obligation    8/14 at 100.00    AAA    2,915,662 
     Bonds, Series 2004, 5.000%, 8/01/21 (Pre-refunded 8/01/14) – FGIC Insured             
2,800    Tobacco Securitization Authority of Southern California, Tobacco Settlement Asset-Backed    6/12 at 100.00    BBB (4)    3,041,976 
     Bonds, San Diego County Tobacco Asset Securitization Corporation, Senior Series 2001A, 5.500%,             
     6/01/36 (Pre-refunded 6/01/12)             
53,705    Total U.S. Guaranteed            57,615,849 
    Utilities – 4.5% (3.0% of Total Investments)             
5,000    Anaheim Public Finance Authority, California, Second Lien Electric Distribution Revenue Bonds,    10/14 at 100.00    AAA    5,331,250 
     Series 2004, 5.250%, 10/01/21 – MBIA Insured             
    Los Angeles Department of Water and Power, California, Power System Revenue Bonds, Series             
    2003A-2:             
750     5.000%, 7/01/21 – MBIA Insured    7/13 at 100.00    AAA    779,138 
1,000     5.000%, 7/01/23 – MBIA Insured    7/13 at 100.00    AAA    1,038,540 
790    Merced Irrigation District, California, Electric System Revenue Bonds, Series 2005, 5.125%,    9/15 at 100.00    AAA    819,396 
     9/01/31 – XLCA Insured             
2,000    Santa Clara, California, Subordinate Electric Revenue Bonds, Series 2003A, 5.250%, 7/01/20 –    7/13 at 100.00    AAA    2,134,640 
     MBIA Insured             
9,540    Total Utilities            10,102,964 
    Water and Sewer – 14.3% (9.5% of Total Investments)             
2,740    California Department of Water Resources, Water System Revenue Bonds, Central Valley Project,    12/12 at 100.00    AAA    2,895,468 
     Series 2002Z, 5.000%, 12/01/18 – FGIC Insured             
4,900    East Bay Municipal Utility District, Alameda and Contra Costa Counties, California, Water    6/11 at 100.00    AAA    5,042,198 
     System Subordinated Revenue Bonds, Series 2001, 5.000%, 6/01/26 – MBIA Insured             
2,655    El Dorado Irrigation District, California, Water and Sewer Certificates of Participation,    3/14 at 100.00    AAA    2,768,209 
     Series 2004A, 5.000%, 3/01/20 – FGIC Insured             
545    Healdsburg Public Financing Authority, California, Wastewater Revenue Bonds, Series 2006,    4/16 at 100.00    AAA    561,835 
     5.000%, 4/01/36 (WI/DD, Settling 6/06/06) – MBIA Insured             
980    Los Angeles Department of Water and Power, California, Waterworks Revenue Bonds, Series    7/16 at 100.00    AAA    1,020,543 
     2006A-2, 5.000%, 7/01/27 – AMBAC Insured             
1,700    San Buenaventura, California, Wastewater Revenue Certificates of Participation, Series 2004,    3/14 at 100.00    AAA    1,757,783 
     5.000%, 3/01/24 – MBIA Insured             
6,885    San Diego Public Facilities Financing Authority, California, Subordinate Lien Water Revenue    8/12 at 100.00    AAA    7,152,276 
     Bonds, Series 2002, 5.000%, 8/01/21 – MBIA Insured             
10,000    San Francisco City and County Public Utilities Commission, California, Clean Water Revenue    4/13 at 100.00    AAA    10,702,100 
     Refunding Bonds, Series 2003A, 5.250%, 10/01/20 – MBIA Insured             
30,405    Total Water and Sewer            31,900,412 
$      318,292    Total Investments (cost $321,900,339) – 150.3%            335,312,191 
    Other Assets Less Liabilities – (1.0)%            (2,212,638) 
    Preferred Shares, at Liquidation Value – (49.3)%            (110,000,000) 
    Net Assets Applicable to Common Shares – 100%           $   223,099,553 

(1)    All percentages shown in the Portfolio of Investments are based on net assets applicable to Common 
    shares unless otherwise noted. 
(2)    Optional Call Provisions: Dates (month and year) and prices of the earliest optional call or redemption. 
    There may be other call provisions at varying prices at later dates. Certain mortgage-backed securities 
    may be subject to periodic principal paydowns. 
(3)    Ratings: Using the higher of Standard & Poor’s or Moody’s rating. Ratings below BBB by Standard & Poor’s 
    Group or Baa by Moody’s Investor Service, Inc. are considered to be below investment grade. 
(4)    Backed by an escrow or trust containing sufficient U.S. Government or U.S. Government agency securities 
    which ensure the timely payment of principal and interest. Such investments are normally considered to 
    be equivalent to AAA rated securities. 
N/R    Not rated. 
WI/DD    Purchased on a when-issued or delayed delivery basis. 

Income Tax Information

The following information is presented on an income tax basis. Differences between amounts for financial statement and federal income tax purposes are primarily due to the treatment of paydown gains and losses, timing differences in recognizing taxable market discount and timing differences in recognizing certain gains and losses on investment transactions.

At May 31, 2006, the cost of investments was $321,887,054.

Gross unrealized appreciation and gross unrealized depreciation of investments at May 31, 2006, were as follows:

Gross unrealized:     
  Appreciation    $13,773,228 
  Depreciation    (348,091) 
Net unrealized appreciation (depreciation) of investments    $13,425,137 

Item 2. Controls and Procedures.

  1. The registrant's principal executive and principal financial officers, or persons performing similar functions, have concluded that the registrant's disclosure controls and procedures (as defined in Rule 30a-3(c) under the Investment Company Act of 1940, as amended (the "1940 Act") (17 CFR 270.30a-3(c))) are effective, as of a date within 90 days of the filing date of this report that includes the disclosure required by this paragraph, based on their evaluation of the controls and procedures required by Rule 30a-3(b) under the 1940 Act (17 CFR 270.30a-3(b)) and Rule 13a-15(b) or 15d-15(b) under the Securities Exchange Act of 1934 (17 CFR 240.13a-15(b) or 240.15d-15(b)).
  2. There were no changes in the registrant's internal control over financial reporting (as defined in Rule 30a-3(d) under the 1940 Act (17 CFR 270.30a-3(d)) that occurred during the registrant's last fiscal quarter that have materially affected, or are reasonably likely to materially affect, the registrant's internal control over financial reporting.

Item 3. Exhibits.

File as exhibits as part of this Form a separate certification for each principal executive officer and principal financial officer of the registrant as required by Rule 30a-2(a) under the 1940 Act (17 CFR 270.30a-2(a)), exactly as set forth below: EX-99 CERT Attached hereto.


SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934 and the Investment Company Act of 1940, the registrant has duly caused this report to be signed on its behalf by the undersigned, thereunto duly authorized.

(Registrant)         Nuveen California Dividend Advantage Municipal Fund 2        

By (Signature and Title)*          /s/ Jessica R. Droeger                     
                                                    Jessica R. Droeger
                                                    Vice President and Secretary

Date         July 28, 2006        

Pursuant to the requirements of the Securities Exchange Act of 1934 and the Investment Company Act of 1940, this report has been signed below by the following persons on behalf of the registrant and in the capacities and on the dates indicated.

By (Signature and Title)*         /s/ Gifford R. Zimmerman                    
                                                   Gifford R. Zimmerman
                                                   Chief Administrative Officer (principal executive officer) 

Date         July 28, 2006        

By (Signature and Title)*         /s/ Stephen D. Foy                              
                                                   Stephen D. Foy
                                                   Vice President and Controller (principal financial officer) 

Date        July 28, 2006        

* Print the name and title of each signing officer under his or her signature.