FORM 4 Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP OF SECURITIES Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934, Section 17(a) of the Public Utility Holding Company Act of 1935 or Section 30(h) of the Investment Company Act of 1940

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1. Name and Address of Reporting Person * Prevost Patrick M.   2. Issuer Name and Ticker or Trading Symbol CABOT CORP [CBT] 5. Relationship of Reporting Person(s) to Issuer (Check all applicable) __X__ Director _____ 10% Owner _____ Officer (give title below) _____ Other (specify below) (Last) (First) (Middle) C/O CABOT CORPORATION, TWO SEAPORT LANE, SUITE 1300 3. Date of Earliest Transaction (Month/Day/Year) 02/17/2017 (Street) BOSTON, MA 02210 4. If Amendment, Date Original Filed(Month/Day/Year) 6. Individual or Joint/Group Filing(Check Applicable Line) _X_ Form filed by One Reporting Person ___ Form filed by More than One Reporting Person (City) (State) (Zip) Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned

1.Title of Security (Instr. 3) 2. Transaction Date (Month/Day/Year) 2A. Deemed Execution Date, if any (Month/Day/Year) 3. Transaction Code (Instr. 8) 4. Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5) 5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4) 6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4) 7. Nature of Indirect Beneficial Ownership (Instr. 4) Code V Amount (A) or (D) Price Common Stock 02/17/2017   M   40,328 A $ 55.37 (1) 293,548 D   Common Stock 02/17/2017   D   12,139 D $ 55.37 (1) 281,409 D   Common Stock 02/21/2017   M   92,562 A $ 34.64 373,971 D   Common Stock 02/21/2017   S   92,562 D $ 58.22 (2) 281,409 D   Common Stock               50.02 (3) I Through the Trustee for the Corporation's 401(k) plan

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Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned
(e.g., puts, calls, warrants, options, convertible securities)

1. Title of Derivative Security (Instr. 3)

2. Conversion or Exercise Price of Derivative Security

3. Transaction Date (Month/Day/Year)

3A. Deemed Execution Date, if any (Month/Day/Year)

4. Transaction Code (Instr. 8)

5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4, and 5)

6. Date Exercisable and Expiration Date (Month/Day/Year)

7. Title and Amount of Underlying Securities (Instr. 3 and 4)

8. Price of Derivative Security (Instr. 5)

9. Number of Derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4)

10. Ownership Form of Derivative Security: Direct (D) or Indirect (I) (Instr. 4)

11. Nature of Indirect Beneficial Ownership (Instr. 4)

Code

V

(A)

(D)

Date Exercisable

Expiration Date

Title

Amount or Number of Shares

Phantom Stock

(4)

02/17/2017

M

40,328

02/17/2017

02/17/2017

Common Stock

40,328

$ 0

0

D

Employee Stock Option (Right to Buy)

$ 34.64

02/21/2017

M

92,562

(5)

10/15/2019

Common Stock

92,562

$ 0

0

D

Reporting Owners

Reporting Owner Name / Address	Relationships
	Director	10% Owner	Officer	Other
Prevost Patrick M. C/O CABOT CORPORATION TWO SEAPORT LANE, SUITE 1300 BOSTON, MA 02210	X

Signatures

By: Kristine L. Ouimet, pursuant to a power of attorney from Patrick M. Prevost		02/22/2017
**Signature of Reporting Person		Date

Explanation of Responses:

*	If the form is filed by more than one reporting person, see Instruction 4(b)(v).
**	Intentional misstatements or omissions of facts constitute Federal Criminal Violations. See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
(1)	The price reported is the closing price of Cabot stock as of January 31, 2017, the date the phantom stock was valued for settlement under the terms of the Supplemental 401(k) Plan.
(2)	The price reported is a weighted average sale price. These shares were sold in multiple transactions at prices ranging from 58.15 to $58.74, inclusive. The reporting person undertakes to provide to the staff of the Securities and Exchange Commission, the Corporation or any security holder of the Corporation, upon request, full information regarding the number of shares sold at each separate price.
(3)	Reflects retirement plan contributions by the Corporation.
(4)	1 for 1
(5)	92,562 shares were subject to the option. The option vested over a three year period as follows: 30% November 12, 2011, 30% November 12, 2012 and 40% on November 12, 2013.

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