PAGE 1 000 B000000 07/31/2003 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 INVESTMENT ADVISORY CORP 008 B000001 A 008 C000001 801-18161 008 D010001 OAKBROOK TERRACE 008 D020001 IL 008 D030001 60181 008 D040001 5555 010 A000001 VAN KAMPEN INVESTMENTS INC 010 B000001 8-19412 010 C010001 OAKBROOK TERRACE 010 C020001 IL 010 C030001 60181 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 PAGE 2 012 A000009 STATE STREET BANK AND TRUST C/O EQUISERVE 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 SECURITIES 014 B000001 8-00000 014 A000002 CHINA INTERNATIONAL CAPITAL CORP LTD 014 B000002 8-00000 014 A000003 HC SECURITIES 014 B000003 8-00000 014 A000004 JM MORGAN STANLEY FIXED INCOME SEC. PRIV. LTD 014 B000004 8-00000 014 A000005 JM MORGAN STANLEY PRIVATE LTD 014 B000005 8-00000 014 A000006 JM MORGAN STANLEY SECURITIES PRIVATE LTD 014 B000006 8-00000 014 A000007 JM MORGAN STANLEY RETAIL SERVICES PRIVATE 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 STANLEY SV SA 014 B000016 8-00000 014 A000017 MORGAN STANLEY DW INC. 014 B000017 8-00000 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. PAGE 3 014 B000021 8-44766 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 E010001 X 015 A000002 DELETE 018 000000 Y 019 A000000 Y 019 B000000 91 019 C000000 VANKAMPENF 020 A000001 JEFFERIES CO INC 020 B000001 95-2622900 020 C000001 8 020 A000002 CANTON FITZGERALD & CO 020 C000002 5 020 C000003 0 020 C000004 0 020 C000005 0 020 C000006 0 020 C000007 0 020 C000008 0 020 C000009 0 020 C000010 0 021 000000 13 022 A000001 STATE STREET BANK AND TRUST 022 B000001 04-1867445 022 C000001 8878277 022 D000001 0 022 A000002 JP MORGAN CHASE 022 B000002 13-3224016 022 C000002 357038 022 D000002 154943 022 A000003 DEUTSCHE BANK AG 022 B000003 13-2944988 022 C000003 275544 022 D000003 94095 022 A000004 BANK AMERICA 022 B000004 95-4035346 022 C000004 214180 PAGE 4 022 D000004 68262 022 A000005 CITIBANK 022 B000005 13-3187336 022 C000005 127066 022 D000005 34692 022 A000006 WACHOVIA BANK 022 C000006 55983 022 D000006 26128 022 A000007 LEHMAN BROTHERS 022 B000007 13-2518466 022 C000007 62689 022 D000007 14660 022 A000008 CREDIT SUISSE FIRST BOSTON 022 C000008 56631 022 D000008 16234 022 A000009 NATIONAL CITY BANK 022 C000009 22141 022 D000009 10424 022 A000010 MIZUHO CORPORATE BANK 022 C000010 0 022 D000010 29987 023 C000000 10273959 023 D000000 541605 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 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 PAGE 5 028 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 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 PAGE 6 048 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 060 B000000 Y 061 000000 0 062 A000000 Y 062 B000000 0.0 062 C000000 0.0 062 D000000 1.7 062 E000000 0.0 062 F000000 0.0 062 G000000 0.0 PAGE 7 062 H000000 0.0 062 I000000 0.0 062 J000000 0.1 062 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 122.3 062 R000000 7.4 063 A000000 0 063 B000000 4.4 064 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 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 PAGE 8 070 P010000 N 070 P020000 N 070 Q010000 N 070 Q020000 N 070 R010000 N 070 R020000 N 071 A000000 1454535 071 B000000 1439852 071 C000000 1845553 071 D000000 78 072 A000000 12 072 B000000 108916 072 C000000 112 072 D000000 0 072 E000000 5576 072 F000000 15924 072 G000000 3747 072 H000000 0 072 I000000 31 072 J000000 511 072 K000000 0 072 L000000 197 072 M000000 119 072 N000000 76 072 O000000 0 072 P000000 8673 072 Q000000 180 072 R000000 70 072 S000000 1142 072 T000000 0 072 U000000 0 072 V000000 0 072 W000000 240 072 X000000 30910 072 Y000000 0 072 Z000000 83694 072AA000000 0 072BB000000 33875 072CC010000 58695 072CC020000 0 072DD010000 79888 072DD020000 0 072EE000000 0 073 A010000 0.4400 073 A020000 0.0000 073 B000000 0.0000 073 C000000 0.0000 074 A000000 0 074 B000000 24200 074 C000000 2211 074 D000000 0 PAGE 9 074 E000000 1207 074 F000000 63681 074 G000000 0 074 H000000 0 074 I000000 1827417 074 J000000 23414 074 K000000 0 074 L000000 7229 074 M000000 179 074 N000000 1949538 074 O000000 86933 074 P000000 1734 074 Q000000 401000 074 R010000 0 074 R020000 0 074 R030000 0 074 R040000 1285 074 S000000 0 074 T000000 1458586 074 U010000 180010 074 U020000 0 074 V010000 8.10 074 V020000 0.00 074 W000000 0.0000 074 X000000 929 074 Y000000 66128 075 A000000 0 075 B000000 1873370 076 000000 7.84 077 A000000 Y 077 B000000 Y 077 C000000 N 077 D000000 N 077 E000000 N 077 F000000 N 077 G000000 N 077 H000000 N 077 I000000 N 077 J000000 N 077 K000000 N 077 L000000 N 077 M000000 N 077 N000000 N 077 O000000 N 077 P000000 N 077 Q010000 N 077 Q020000 N 077 Q030000 N 078 000000 N 080 A000000 ICI MUTUAL INSURANCE COMPANY 080 C000000 85000 PAGE 10 081 A000000 Y 081 B000000 102 082 A000000 Y 082 B000000 100 083 A000000 N 083 B000000 0 084 A000000 N 084 B000000 0 085 A000000 Y 085 B000000 N 086 A010000 0 086 A020000 0 086 B010000 0 086 B020000 0 086 C010000 0 086 C020000 0 086 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