PAGE 1
000 A000000 01/31/2004
000 C000000 0001059386
000 D000000 N
000 E000000 NF
000 F000000 Y
000 G000000 N
000 H000000 N
000 I000000 6.1
000 J000000 A
001 A000000 VAN KAMPEN SENIOR INCOME TRUST
001 B000000 811-08743
001 C000000 2127625260
002 A000000 1221 AVENUE OF THE AMERICAS
002 B000000 NEW YORK
002 C000000 NY
002 D010000 10020
003 000000 N
004 000000 N
005 000000 N
006 000000 N
007 A000000 N
007 B000000 0
007 C010100 1
007 C010200 2
007 C010300 3
007 C010400 4
007 C010500 5
007 C010600 6
007 C010700 7
007 C010800 8
007 C010900 9
007 C011000 10
008 A000001 VAN KAMPEN ASSET MANAGEMENT
008 B000001 A
008 C000001 801-1669
008 D010001 NEW YORK
008 D020001 NY
008 D030001 10020
010 A000001 VAN KAMPEN INVESTMENTS INC
010 B000001 8-19412
010 C010001 NEW YORK
010 C020001 NY
010 C030001 10020
011 A000001 DELETE
012 A000001 STATE STREET BANK & TRUST CO. C/O EQUISERVE
012 B000001 85-11340
012 C010001 PROVIDENCE
012 C020001 RI
012 C030001 02940
012 C040001 3011
012 A000009 STATE STREET BANK AND TRUST C/O EQUISERVE
PAGE 2
012 B000009 85-5003
012 C010009 PROVIDENCE
012 C020009 RI
012 C030009 02940
012 C040009 3011
013 A000001 DELOITTE & TOUCHE LLP
013 B010001 CHICAGO
013 B020001 IL
013 B030001 60601
014 A000001 ARAB MALAYSIA SECURTIES
014 B000001 8-00000
014 A000002 CHINA INTERNATIONAL CAPITAL CORP. LTD
014 B000002 8-00000
014 A000003 HC SECURTITIES
014 B000003 8-00000
014 A000004 JM MORGAN STANLEY FIXED INCOME SEC. PRIV. LTD
014 B000004 8-00000
014 A000005 JM MORGAN STANLEY PRIVATED LTD
014 B000005 8-00000
014 A000006 JM MORGAN STANLEY SECURITIES PRIVATE LTD
014 B000006 8-00000
014 A000007 JM MORGAN STANLEY RETAIL SERVICES PRIV. LTD
014 B000007 8-00000
014 A000008 MORGAN STANLEY & CO. INC.
014 B000008 8-15869
014 A000009 MORGAN STANLEY & CO. LTD
014 B000009 8-00000
014 A000010 MORGAN STANLEY ASIA LTD
014 B000010 8-00000
014 A000011 MORGAN STANLEY CANADA LTD
014 B000011 8-00000
014 A000012 MORGAN STANLEY QUILTER LTD
014 B000012 8-00000
014 A000013 MORGAN STANLEY DW AUSTRALIA SEC. LTD
014 B000013 8-00000
014 A000014 MORGAN STANLEY JAPAN LTD
014 B000014 8-00000
014 A000015 MORGAN STANLEY NIPPON SECURITIES LTD
014 B000015 8-00000
014 A000016 MORGAN STANELY SV SA .
014 B000016 8-00000
014 A000017 MORGAN STANELY DW INC.
014 B000017 8-14172
014 A000018 MORGAN STANLEY INTERNATIONAL LTD
014 B000018 8-00000
014 A000019 MORGAN STANLEY SECURITIES LTD
014 B000019 8-00000
014 A000020 MORGAN STANLEY BANK AG
014 B000020 8-00000
014 A000021 MORGAN STANLEY DISTRIBUTION INC.
014 B000021 8-44766
PAGE 3
014 A000022 MORGAN STANLEY DISTRIBUTORS INC.
014 B000022 8-45262
014 A000023 MORGAN STANLEY MARKET PRODUCTS INC.
014 B000023 8-37795
014 A000024 MS SECURITIES SERVICES INC.
014 B000024 8-26804
014 A000025 PRIME DEALER SERVICES CORP.
014 B000025 8-47025
014 A000026 VAN KAMPEN FUNDS INC.
014 B000026 8-19412
015 A000001 STATE STREET BANK AND TRUST CO.
015 B000001 C
015 C010001 BOSTON
015 C020001 MA
015 C030001 02110
015 C040001 1713
015 E010001 X
015 A000002 DELETE
018 000000 Y
019 A000000 Y
019 B000000 88
019 C000000 VANKAMPENF
020 A000001 JEFFERIES CO INC
020 B000001 95-2622900
020 C000001 24
020 A000002 CREDIT SUISSE FIRST BOSTON
020 B000002 13-5659485
020 C000002 22
020 A000003 CANTOR FITZGERALD & CO.
020 B000003 13-3121110
020 C000003 4
020 A000004 LEHMAN BROTHERS INC.
020 B000004 13-2518466
020 C000004 2
020 C000005 0
020 C000006 0
020 C000007 0
020 C000008 0
020 C000009 0
020 C000010 0
021 000000 52
022 A000001 STATE STREET BANK
022 B000001 04-1867445
022 C000001 3919348
022 D000001 5300
022 A000002 JP MORGAN CHASE
022 B000002 13-3224016
022 C000002 521932
022 D000002 53960
022 A000003 BANK OF AMERICA
022 B000003 95-4035346
PAGE 4
022 C000003 166769
022 D000003 20475
022 A000004 DEUTSCHE BANK AG
022 B000004 13-2944988
022 C000004 79513
022 D000004 10131
022 A000005 LEHMAN BROTHERS
022 B000005 95-4035346
022 C000005 70547
022 D000005 17423
022 A000006 CREDIT SUISSE FIRST BOSTON
022 B000006 13-5659485
022 C000006 63012
022 D000006 19465
022 A000007 CITIBANK
022 B000007 13-3187336
022 C000007 49975
022 D000007 15224
022 A000008 BANK OF NEW YORK
022 B000008 13-5160382
022 C000008 29856
022 D000008 12909
022 A000009 FLEET BOSTON FINANCIAL CORP.
022 B000009 05-0341324
022 C000009 14509
022 D000009 8919
022 A000010 UBS AG
022 B000010 13-2932996
022 C000010 12566
022 D000010 8145
023 C000000 5067145
023 D000000 181032
024 000000 N
025 D000001 0
025 D000002 0
025 D000003 0
025 D000004 0
025 D000005 0
025 D000006 0
025 D000007 0
025 D000008 0
026 A000000 N
026 B000000 Y
026 C000000 Y
026 D000000 Y
026 E000000 N
026 F000000 Y
026 G010000 N
026 G020000 N
026 H000000 N
027 000000 N
PAGE 5
028 A010000 0
028 A020000 0
028 A030000 0
028 A040000 0
028 B010000 0
028 B020000 0
028 B030000 0
028 B040000 0
028 C010000 0
028 C020000 0
028 C030000 0
028 C040000 0
028 D010000 0
028 D020000 0
028 D030000 0
028 D040000 0
028 E010000 0
028 E020000 0
028 E030000 0
028 E040000 0
028 F010000 0
028 F020000 0
028 F030000 0
028 F040000 0
028 G010000 0
028 G020000 0
028 G030000 0
028 G040000 0
028 H000000 0
030 A000000 0
030 B000000 0.00
030 C000000 0.00
031 A000000 0
031 B000000 0
032 000000 0
033 000000 0
035 000000 0
036 B000000 0
038 000000 0
042 A000000 0
042 B000000 0
042 C000000 0
042 D000000 0
042 E000000 0
042 F000000 0
042 G000000 0
042 H000000 0
043 000000 0
044 000000 0
045 000000 Y
046 000000 N
PAGE 6
047 000000 Y
048 000000 0.850
048 A010000 0
048 A020000 0.000
048 B010000 0
048 B020000 0.000
048 C010000 0
048 C020000 0.000
048 D010000 0
048 D020000 0.000
048 E010000 0
048 E020000 0.000
048 F010000 0
048 F020000 0.000
048 G010000 0
048 G020000 0.000
048 H010000 0
048 H020000 0.000
048 I010000 0
048 I020000 0.000
048 J010000 0
048 J020000 0.000
048 K010000 0
048 K020000 0.000
049 000000 N
050 000000 N
051 000000 N
052 000000 N
053 A000000 N
054 A000000 Y
054 B000000 N
054 C000000 N
054 D000000 N
054 E000000 N
054 F000000 N
054 G000000 Y
054 H000000 Y
054 I000000 N
054 J000000 Y
054 K000000 N
054 L000000 N
054 M000000 Y
054 N000000 N
054 O000000 Y
055 A000000 N
055 B000000 N
056 000000 N
057 000000 N
058 A000000 N
059 000000 Y
060 A000000 Y
PAGE 7
060 B000000 Y
061 000000 0
062 A000000 Y
062 B000000 0.0
062 C000000 0.0
062 D000000 3.8
062 E000000 0.0
062 F000000 0.0
062 G000000 0.0
062 H000000 0.0
062 I000000 0.0
062 J000000 0.0
062 K000000 0.0
062 L000000 0.0
062 M000000 0.0
062 N000000 0.0
062 O000000 0.0
062 P000000 0.0
062 Q000000 140.1
062 R000000 4.4
063 A000000 0
063 B000000 4.5
064 A000000 Y
064 B000000 Y
065 000000 Y
066 A000000 N
067 000000 N
068 A000000 N
068 B000000 N
069 000000 N
070 A010000 Y
070 A020000 Y
070 B010000 N
070 B020000 N
070 C010000 Y
070 C020000 N
070 D010000 N
070 D020000 N
070 E010000 Y
070 E020000 N
070 F010000 N
070 F020000 N
070 G010000 Y
070 G020000 N
070 H010000 N
070 H020000 N
070 I010000 N
070 I020000 N
070 J010000 Y
070 J020000 Y
070 K010000 Y
PAGE 8
070 K020000 N
070 L010000 Y
070 L020000 Y
070 M010000 Y
070 M020000 N
070 N010000 Y
070 N020000 N
070 O010000 Y
070 O020000 Y
070 P010000 N
070 P020000 N
070 Q010000 N
070 Q020000 N
070 R010000 N
070 R020000 N
071 A000000 1047388
071 B000000 795783
071 C000000 2053109
071 D000000 39
072 A000000 6
072 B000000 50843
072 C000000 84
072 D000000 0
072 E000000 2856
072 F000000 8713
072 G000000 2050
072 H000000 0
072 I000000 18
072 J000000 272
072 K000000 0
072 L000000 101
072 M000000 57
072 N000000 38
072 O000000 0
072 P000000 3068
072 Q000000 106
072 R000000 34
072 S000000 381
072 T000000 0
072 U000000 0
072 V000000 0
072 W000000 1064
072 X000000 15902
072 Y000000 0
072 Z000000 37881
072AA000000 1272
072BB000000 0
072CC010000 76901
072CC020000 0
072DD010000 35750
072DD020000 0
PAGE 9
072EE000000 0
073 A010000 0.2000
073 A020000 0.0000
073 B000000 0.0000
073 C000000 0.0000
074 A000000 444
074 B000000 58000
074 C000000 0
074 D000000 0
074 E000000 1073
074 F000000 67036
074 G000000 0
074 H000000 0
074 I000000 2156287
074 J000000 1587
074 K000000 0
074 L000000 8825
074 M000000 176
074 N000000 2293428
074 O000000 86179
074 P000000 2026
074 Q000000 665000
074 R010000 0
074 R020000 0
074 R030000 0
074 R040000 1333
074 S000000 0
074 T000000 1538890
074 U010000 180010
074 U020000 0
074 V010000 8.55
074 V020000 0.00
074 W000000 0.0000
074 X000000 894
074 Y000000 111482
075 A000000 0
075 B000000 2038960
076 000000 8.70
077 A000000 N
078 000000 N
080 C000000 0
081 B000000 0
082 B000000 0
083 B000000 0
084 B000000 0
086 A010000 0
086 A020000 0
086 B010000 0
086 B020000 0
086 C010000 0
086 C020000 0
PAGE 10
086 D010000 0
086 D020000 0
086 E010000 0
086 E020000 0
086 F010000 0
086 F020000 0
087 A010000 COMMON
087 A020000 920961109
087 A030000 VVR
088 A000000 N
088 B000000 N
088 C000000 N
088 D000000 N
SIGNATURE MICHAEL COYNE
TITLE ASSISTANT TREASURER