PAGE  1
000 A000000 04/30/2005
000 C000000 0001275214
000 D000000 N
000 E000000 NF
000 F000000 Y
000 G000000 N
000 H000000 N
000 I000000 6.1
000 J000000 A
001 A000000 CALAMOS STRATEGIC TOTAL RETURN FUND
001 B000000 811-21484
001 C000000 6302457200
002 A000000 1111 WARRENVILLE ROAD
002 B000000 NAPERVILLE
002 C000000 IL
002 D010000 60563
003  000000 N
004  000000 N
005  000000 N
006  000000 N
007 A000000 N
007 B000000  0
007 C010100  1
008 A000001 CALAMOS ADVISORS LLC
008 B000001 A
008 C000001 801-29688
008 D010001 NAPERVILLE
008 D020001 IL
008 D030001 60563
010 A000001 STATE STREET CORPORATION
010 B000001 01-07511
010 C010001 BOSTON
010 C020001 MA
010 C030001 02110
012 A000001 BANK OF NEW YORK (COMMON)
012 B000001 85-05006
012 C010001 NEW YORK
012 C020001 NY
012 C030001 10286
012 A000002 BANK OF NEW YORK (PREFERRED)
012 B000002 85-05006
012 C010002 NEW YORK
012 C020002 NY
012 C030002 10286
013 A000001 DELOITTE & TOUCHE, LLP
013 B010001 CHICAGO
013 B020001 IL
013 B030001 60601
014 A000001 CALAMOS FINANCIAL SERVICES, INC.
014 B000001 8-37854
015 A000001 BANK OF NEW YORK
      PAGE  2
015 B000001 C
015 C010001 NEW YORK
015 C020001 NY
015 C030001 10286
015 E010001 X
015 A000002 EUROCLEAR BANK
015 B000002 S
015 C010002 BRUSSELS
015 D010002 BELGIUM
015 E040002 X
015 A000003 BNY LONDON - CREST
015 B000003 S
015 C010003 LONDON
015 D010003 UNITED KINGDOM
015 E040003 X
015 A000004 Bank Austria AG
015 B000004 C
015 C010004 Vienna
015 D010004 Austria
015 E040004 X
015 A000005 Royal Bank of Canada
015 B000005 S
015 C010005 Toronto
015 D010005 Canada
015 E040005 X
015 A000006 DELETE
018  000000 Y
019 A000000 Y
019 B000000   13
019 C000000 CALAMOSINV
020 A000001 SUSQUEHANNA INVESTMENT GROUP
020 B000001 23-2454154
020 C000001    235
020 A000002 BANK OF AMERICA SECURITIES LLC
020 B000002 56-2058405
020 C000002    217
020 A000003 GOLDMAN, SACHS & CO.
020 B000003 13-5108880
020 C000003    137
020 A000004 UBS SECURITIES LLC
020 B000004 13-3873456
020 C000004     86
020 A000005 MERRILL LYNCH
020 B000005 13-2740599
020 C000005     80
020 A000006 LEHMAN BROTHERS
020 B000006 13-2518466
020 C000006     35
020 A000007 LIQUIDNET, INC
020 B000007 13-4095933
020 C000007     34
      PAGE  3
020 A000008 STANDARD & POOR'S SECURITIES, INC.
020 B000008 13-2671951
020 C000008     30
020 A000009 KV EXECUTION SERVICES LLC
020 B000009 13-3838570
020 C000009     27
020 A000010 CITIGROUP GLOBAL MARKETS, INC.
020 B000010 11-2418191
020 C000010     24
021  000000     1175
022 A000001 BNY CAPITAL MARKETS, INC.
022 B000001 13-3878175
022 C000001   5313408
022 D000001      5490
022 A000002 CITIGROUP GLOBAL MARKETS, INC.
022 B000002 11-2418191
022 C000002    572403
022 D000002    516535
022 A000003 J.P. MORGAN SECURITIES INC.
022 B000003 13-3224016
022 C000003    106981
022 D000003     95810
022 A000004 BANK OF AMERICA SECURITIES LLC
022 B000004 56-2058405
022 C000004     44914
022 D000004     45794
022 A000005 MORGAN STANLEY
022 B000005 13-2655998
022 C000005     37970
022 D000005     41300
022 A000006 BEAR STEARNS & CO., INC.
022 B000006 13-3299429
022 C000006     26186
022 D000006     40343
022 A000007 UBS SECURITIES LLC
022 B000007 13-3873456
022 C000007     12617
022 D000007     46118
022 A000008 GOLDMAN, SACHS & CO.
022 B000008 13-5108880
022 C000008     32834
022 D000008     25787
022 A000009 MERRILL LYNCH
022 B000009 13-2740599
022 C000009     27547
022 D000009     30255
022 A000010 CREDIT SUISSE FIRST BOSTON
022 B000010 13-2853402
022 C000010     32211
022 D000010     19597
023 C000000    6278560
      PAGE  4
023 D000000     907439
024  000000 Y
025 A000001 BANK OF AMERICA SECURITIES LLC
025 B000001 56-2058405
025 C000001 E
025 D000001   44139
025 A000002 CITIGROUP GLOBAL MARKETS, INC.
025 B000002 11-2418191
025 C000002 E
025 D000002   64429
025 A000003 LEHMAN BROTHERS
025 B000003 13-2518466
025 C000003 E
025 D000003   22500
025 A000004 MERRILL LYNCH
025 B000004 13-2740599
025 C000004 E
025 D000004   15894
026 A000000 N
026 B000000 Y
026 C000000 N
026 D000000 Y
026 E000000 N
026 F000000 N
026 G010000 N
026 G020000 N
026 H000000 N
027  000000 N
045  000000 Y
046  000000 N
047  000000 Y
048  000000  1.000
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
      PAGE  6
048 K020000 0.000
049  000000 N
050  000000 N
051  000000 N
052  000000 N
053 A000000 N
054 A000000 Y
054 B000000 Y
054 C000000 N
054 D000000 N
054 E000000 N
054 F000000 N
054 G000000 N
054 H000000 Y
054 I000000 N
054 J000000 Y
054 K000000 N
054 L000000 N
054 M000000 Y
054 N000000 N
054 O000000 N
055 A000000 N
055 B000000 N
056  000000 Y
057  000000 N
058 A000000 N
059  000000 Y
060 A000000 Y
060 B000000 Y
061  000000        0
062 A000000 N
062 B000000   0.0
062 C000000   0.0
062 D000000   0.0
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   0.0
062 R000000   0.0
063 A000000   0
063 B000000  0.0
066 A000000 Y
      PAGE  7
066 B000000 N
066 C000000 N
066 D000000 N
066 E000000 N
066 F000000 N
066 G000000 Y
067  000000 N
068 A000000 N
068 B000000 N
069  000000 N
070 A010000 Y
070 A020000 N
070 B010000 Y
070 B020000 Y
070 C010000 Y
070 C020000 N
070 D010000 Y
070 D020000 N
070 E010000 Y
070 E020000 N
070 F010000 Y
070 F020000 N
070 G010000 Y
070 G020000 N
070 H010000 Y
070 H020000 N
070 I010000 Y
070 I020000 N
070 J010000 Y
070 J020000 Y
070 K010000 Y
070 K020000 Y
070 L010000 Y
070 L020000 Y
070 M010000 Y
070 M020000 Y
070 N010000 Y
070 N020000 Y
070 O010000 Y
070 O020000 N
070 P010000 Y
070 P020000 N
070 Q010000 N
070 Q020000 N
070 R010000 Y
070 R020000 N
071 A000000   1448726
071 B000000   1447329
071 C000000   3324791
071 D000000   43
072 A000000  6
      PAGE  8
072 B000000    52317
072 C000000    39169
072 D000000        0
072 E000000     1014
072 F000000    16786
072 G000000        0
072 H000000        0
072 I000000     1390
072 J000000      109
072 K000000        0
072 L000000      325
072 M000000       14
072 N000000       67
072 O000000        0
072 P000000        0
072 Q000000      428
072 R000000       46
072 S000000       21
072 T000000        0
072 U000000        0
072 V000000        0
072 W000000       36
072 X000000    19222
072 Y000000        0
072 Z000000    73278
072AA000000    74962
072BB000000     4620
072CC010000        0
072CC020000    30238
072DD010000    71463
072DD020000        0
072EE000000        0
073 A010000   0.4625
073 A020000   0.0000
073 B000000   0.0000
073 C000000   0.0000
074 A000000      150
074 B000000        0
074 C000000    21372
074 D000000  1259883
074 E000000   425170
074 F000000  1562303
074 G000000    18803
074 H000000        0
074 I000000   506063
074 J000000     8068
074 K000000        0
074 L000000    37342
074 M000000     2465
074 N000000  3841619
074 O000000    11581
      PAGE  9
074 P000000     2763
074 Q000000        0
074 R010000        0
074 R020000        0
074 R030000     3087
074 R040000   516069
074 S000000  1080746
074 T000000  2227373
074 U010000   154514
074 U020000        0
074 V010000    14.42
074 V020000     0.00
074 W000000   0.0000
074 X000000       83
074 Y000000        0
075 A000000        0
075 B000000  2290372
076  000000    13.57
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
086 D010000      0
086 D020000      0
086 E010000      0
086 E020000      0
086 F010000      0
086 F020000      0
087 A010000 COMMON STOCK
087 A020000 128125101
087 A030000 CSQ
087 B010000 PREFERRED STOCK
088 A000000 N
088 B000000 N
088 C000000 N
088 D000000 Y
SIGNATURE   NIMISH S. BHATT
TITLE       TREASURER