<PAGE> PAGE 1
000 B000000 12/31/98
000 C000000 014358
000 D000000 N
000 E000000 NF
000 F000000 Y
000 G000000 N
000 H000000 N
000 I000000 3.0.a
000 J000000 A
001 A000000 SELIGMAN COMMON STOCK FUND, INC.
001 B000000 811-234
001 C000000 2128501864
002 A000000 100 PARK AVENUE
002 B000000 NEW YORK
002 C000000 NY
002 D010000 10017
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 J & W SELIGMAN & CO. INCORPORATED
008 B000001 A
008 C000001 801-15798
008 D010001 NEW YORK
008 D020001 NY
008 D030001 10017
008 A000002 DELETE
011 A000001 SELIGMAN ADVISORS, INC.
011 B000001 8-25845
011 C010001 NEW YORK
011 C020001 NY
011 C030001 10017
012 A000001 SELIGMAN DATA CORP.
012 B000001 84-1895
012 C010001 NEW YORK
012 C020001 NY
012 C030001 10017
013 A000001 DELOITTE & TOUCHE LLP
013 B010001 NEW YORK
<PAGE> PAGE 2
013 B020001 NY
013 B030001 10281
014 A000001 SELIGMAN SERVICES, INC.
014 B000001 8-47717
015 A000001 INVESTORS FIDUCIARY TRUST CO.
015 B000001 C
015 C010001 KANSAS CITY
015 C020001 MO
015 C030001 64105
015 C040001 1307
015 E010001 X
015 A000002 CHASE MANHATTAN BANK
015 B000002 S
015 C010002 NEW YORK
015 C020002 NY
015 C030002 10036
015 E040002 X
018 000000 Y
019 A000000 Y
019 B000000 52
019 C000000 JWSELIGMAN
020 A000001 DONALDSON, LUFKIN & JENRETTE SECURITIES CORP.
020 B000001 13-2741729
020 C000001 249
020 A000002 WEEDEN & CO. L.P.
020 B000002 13-3364318
020 C000002 521
020 A000003 PAINEWEBBER, INC.
020 B000003 13-2638166
020 C000003 85
020 A000004 MORGAN STANLEY & CO., INC.
020 B000004 13-2655998
020 C000004 84
020 A000005 LEHMAN BROTHERS INC.
020 B000005 13-2518466
020 C000005 94
020 A000006 MERRILL LYNCH, PIERCE, FENNER & SMITH, INC.
020 B000006 13-5674085
020 C000006 46
020 A000007 AUTRANET, INC.
020 B000007 13-2961507
020 C000007 74
020 A000008 GOLDMAN SACHS & CO.
020 B000008 13-5108880
020 C000008 49
020 A000009 SMITH BARNEY, INC.
020 B000009 13-1912900
020 C000009 166
020 A000010 BRIDGE TRADING COMPANY
020 B000010 43-1450530
020 C000010 59
<PAGE> PAGE 3
021 000000 2075
022 A000001 UBS-GRAND CAYMAN
022 B000001 13-2795530
022 C000001 1403277
022 D000001 8184
022 A000002 BANK OF MONTREAL-TORONTO
022 B000002 13-4941092
022 C000002 1649160
022 D000002 0
022 A000003 REPUBLIC NATIONAL BK OF NEW YORK-GRAND CAYMAN
022 B000003 13-2774726
022 C000003 1305983
022 D000003 0
022 A000004 CANADIAN IMPERIAL BK OF COMMERCE-GRAND CAYMAN
022 B000004 13-1942440
022 C000004 1560905
022 D000004 0
022 A000005 NATIONAL WESTMINSTER BANK-GRAND CAYMAN
022 B000005 13-5634601
022 C000005 804204
022 D000005 0
022 A000006 FIRST NATIONAL BANK OF CHICAGO-GRAND CAYMAN
022 B000006 36-0899825
022 C000006 1403403
022 D000006 0
022 A000007 BANK OF NOVA SCOTIA-GRAND CAYMAN
022 B000007 03-8405740
022 C000007 817692
022 D000007 0
022 A000008 CREDIT COMMUNAL DE BELGIQUE-GRAND CAYMAN
022 B000008 13-3915825
022 C000008 902377
022 D000008 0
022 A000009 BAYERISCHE VEREINSBANK-GRAND CAYMAN
022 B000009 13-2774123
022 C000009 638710
022 D000009 0
022 A000010 STATE STREET BANK & TRUST CO.-GRAND CAYMAN
022 B000010 04-1867445
022 C000010 466919
022 D000010 0
023 C000000 11335928
023 D000000 51127
024 000000 N
025 D000001 0
025 D000002 0
025 D000003 0
025 D000004 0
025 D000005 0
025 D000006 0
025 D000007 0
<PAGE> PAGE 4
025 D000008 0
025 D000009 0
025 D000010 0
025 D000011 0
025 D000012 0
025 D000013 0
025 D000014 0
025 D000015 0
025 D000016 0
026 A000000 Y
026 B000000 Y
026 C000000 Y
026 D000000 Y
026 E000000 N
026 F000000 Y
026 G010000 N
026 G020000 N
026 H000000 Y
027 000000 Y
028 A010000 20477
028 A020000 0
028 A030000 0
028 A040000 28856
028 B010000 14282
028 B020000 0
028 B030000 0
028 B040000 23340
028 C010000 32379
028 C020000 2130
028 C030000 0
028 C040000 38266
028 D010000 24529
028 D020000 0
028 D030000 0
028 D040000 24329
028 E010000 13995
028 E020000 52326
028 E030000 0
028 E040000 19754
028 F010000 21733
028 F020000 0
028 F030000 0
028 F040000 22958
028 G010000 127395
028 G020000 54456
028 G030000 0
028 G040000 157503
028 H000000 4724
029 000000 Y
030 A000000 508
030 B000000 4.75
<PAGE> PAGE 5
030 C000000 0.00
031 A000000 58
031 B000000 0
032 000000 426
033 000000 24
034 000000 Y
035 000000 106
036 A000000 N
036 B000000 0
037 000000 N
038 000000 0
039 000000 N
040 000000 Y
041 000000 Y
042 A000000 0
042 B000000 0
042 C000000 0
042 D000000 100
042 E000000 0
042 F000000 0
042 G000000 0
042 H000000 0
043 000000 2924
044 000000 0
045 000000 Y
046 000000 N
047 000000 Y
048 000000 0.000
048 A010000 1000000
048 A020000 0.650
048 B010000 1000000
048 B020000 0.600
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 2000000
048 K020000 0.550
049 000000 N
<PAGE> PAGE 6
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 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 Y
055 B000000 N
056 000000 Y
057 000000 N
058 A000000 N
059 000000 Y
060 A000000 Y
060 B000000 Y
061 000000 1000
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
066 B000000 N
066 C000000 N
<PAGE> PAGE 7
066 D000000 N
066 E000000 Y
066 F000000 N
066 G000000 N
067 000000 N
068 A000000 N
068 B000000 N
069 000000 N
070 A010000 Y
070 A020000 N
070 B010000 N
070 B020000 N
070 C010000 N
070 C020000 N
070 D010000 N
070 D020000 N
070 E010000 N
070 E020000 N
070 F010000 N
070 F020000 N
070 G010000 N
070 G020000 N
070 H010000 N
070 H020000 N
070 I010000 N
070 I020000 N
070 J010000 Y
070 J020000 Y
070 K010000 N
070 K020000 N
070 L010000 Y
070 L020000 Y
070 M010000 Y
070 M020000 Y
070 N010000 Y
070 N020000 N
070 O010000 Y
070 O020000 N
070 P010000 Y
070 P020000 Y
070 Q010000 N
070 Q020000 N
070 R010000 N
070 R020000 N
071 A000000 755552
071 B000000 783919
071 C000000 806569
071 D000000 94
072 A000000 12
072 B000000 2550
072 C000000 21888
<PAGE> PAGE 8
072 D000000 0
072 E000000 20
072 F000000 5595
072 G000000 0
072 H000000 0
072 I000000 1241
072 J000000 176
072 K000000 71
072 L000000 117
072 M000000 22
072 N000000 86
072 O000000 0
072 P000000 0
072 Q000000 0
072 R000000 65
072 S000000 24
072 T000000 2924
072 U000000 0
072 V000000 0
072 W000000 32
072 X000000 10353
072 Y000000 0
072 Z000000 14105
072AA000000 146788
072BB000000 43325
072CC010000 19254
072CC020000 0
072DD010000 13006
072DD020000 851
072EE000000 128667
073 A010000 0.2820
073 A020000 0.1660
073 B000000 2.4680
073 C000000 0.0000
074 A000000 556
074 B000000 0
074 C000000 44535
074 D000000 0
074 E000000 0
074 F000000 832738
074 G000000 0
074 H000000 0
074 I000000 23
074 J000000 0
074 K000000 153
074 L000000 5146
074 M000000 54
074 N000000 883205
074 O000000 0
074 P000000 753
074 Q000000 0
<PAGE> PAGE 9
074 R010000 0
074 R020000 0
074 R030000 0
074 R040000 1595
074 S000000 0
074 T000000 880857
074 U010000 48190
074 U020000 5444
074 V010000 15.77
074 V020000 15.73
074 W000000 0.0000
074 X000000 27828
074 Y000000 0
075 A000000 0
075 B000000 860696
076 000000 0.00
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 Y
077 Q020000 N
077 Q030000 N
078 000000 N
080 A000000 ICI MUTUAL INSURANCE CO.
080 C000000 22000
081 A000000 Y
081 B000000 65
082 A000000 Y
082 B000000 150
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
<PAGE> PAGE 10
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
SIGNATURE THOMAS G. ROSE
TITLE TREASURER
<TABLE> <S> <C>
<ARTICLE> 6
<SERIES>
<NUMBER> 001
<NAME> SELIGMAN COMMON STOCK FUND, INC. CLASS A
<MULTIPLIER> 1000
<S> <C>
<PERIOD-TYPE> 12-MOS
<FISCAL-YEAR-END> DEC-31-1998
<PERIOD-END> DEC-31-1998
<INVESTMENTS-AT-COST> 648314
<INVESTMENTS-AT-VALUE> 877273
<RECEIVABLES> 5300
<ASSETS-OTHER> 632
<OTHER-ITEMS-ASSETS> 0
<TOTAL-ASSETS> 883205
<PAYABLE-FOR-SECURITIES> 0
<SENIOR-LONG-TERM-DEBT> 0
<OTHER-ITEMS-LIABILITIES> 2348
<TOTAL-LIABILITIES> 2348
<SENIOR-EQUITY> 0
<PAID-IN-CAPITAL-COMMON> 641391
<SHARES-COMMON-STOCK> 48190<F1>
<SHARES-COMMON-PRIOR> 46135<F1>
<ACCUMULATED-NII-CURRENT> 0
<OVERDISTRIBUTION-NII> (178)
<ACCUMULATED-NET-GAINS> 10685
<OVERDISTRIBUTION-GAINS> 0
<ACCUM-APPREC-OR-DEPREC> 228959
<NET-ASSETS> 760176<F1>
<DIVIDEND-INCOME> 19075<F1>
<INTEREST-INCOME> 2222<F1>
<OTHER-INCOME> 18<F1>
<EXPENSES-NET> (8291)<F1>
<NET-INVESTMENT-INCOME> 13006<F1>
<REALIZED-GAINS-CURRENT> 103463
<APPREC-INCREASE-CURRENT> 19254
<NET-CHANGE-FROM-OPS> 136822
<EQUALIZATION> (24419)
<DISTRIBUTIONS-OF-INCOME> (13006)<F1>
<DISTRIBUTIONS-OF-GAINS> (111760)<F1>
<DISTRIBUTIONS-OTHER> 0
<NUMBER-OF-SHARES-SOLD> 9205<F1>
<NUMBER-OF-SHARES-REDEEMED> (12695)<F1>
<SHARES-REINVESTED> 5545<F1>
<NET-CHANGE-IN-ASSETS> 45757
<ACCUMULATED-NII-PRIOR> 0
<ACCUMULATED-GAINS-PRIOR> 60308
<OVERDISTRIB-NII-PRIOR> (247)
<OVERDIST-NET-GAINS-PRIOR> 0
<GROSS-ADVISORY-FEES> 4875<F1>
<INTEREST-EXPENSE> 0
<GROSS-EXPENSE> 8291<F1>
<AVERAGE-NET-ASSETS> 750065<F1>
<PER-SHARE-NAV-BEGIN> 15.92<F1>
<PER-SHARE-NII> .28<F1>
<PER-SHARE-GAIN-APPREC> 2.32<F1>
<PER-SHARE-DIVIDEND> (.28)<F1>
<PER-SHARE-DISTRIBUTIONS> (2.47)<F1>
<RETURNS-OF-CAPITAL> 0<F1>
<PER-SHARE-NAV-END> 15.77<F1>
<EXPENSE-RATIO> 1.11<F1>
<AVG-DEBT-OUTSTANDING> 0
<AVG-DEBT-PER-SHARE> 0
<FN>
<F1>Class A only. All other data are fund level.
</FN>
</TABLE>
<TABLE> <S> <C>
<ARTICLE> 6
<SERIES>
<NUMBER> 002
<NAME> SELIGMAN COMMON STOCK FUND, INC. CLASS B
<MULTIPLIER> 1000
<S> <C>
<PERIOD-TYPE> 12-MOS
<FISCAL-YEAR-END> DEC-31-1998
<PERIOD-END> DEC-31-1998
<INVESTMENTS-AT-COST> 648314
<INVESTMENTS-AT-VALUE> 877273
<RECEIVABLES> 5300
<ASSETS-OTHER> 632
<OTHER-ITEMS-ASSETS> 0
<TOTAL-ASSETS> 883205
<PAYABLE-FOR-SECURITIES> 0
<SENIOR-LONG-TERM-DEBT> 0
<OTHER-ITEMS-LIABILITIES> 2348
<TOTAL-LIABILITIES> 2348
<SENIOR-EQUITY> 0
<PAID-IN-CAPITAL-COMMON> 641391
<SHARES-COMMON-STOCK> 2232<F1>
<SHARES-COMMON-PRIOR> 1232<F1>
<ACCUMULATED-NII-CURRENT> 0
<OVERDISTRIBUTION-NII> (178)
<ACCUMULATED-NET-GAINS> 10685
<OVERDISTRIBUTION-GAINS> 0
<ACCUM-APPREC-OR-DEPREC> 228959
<NET-ASSETS> 35073<F1>
<DIVIDEND-INCOME> 705<F1>
<INTEREST-INCOME> 82<F1>
<OTHER-INCOME> 0<F1>
<EXPENSES-NET> (517)<F1>
<NET-INVESTMENT-INCOME> 270<F1>
<REALIZED-GAINS-CURRENT> 103463
<APPREC-INCREASE-CURRENT> 19254
<NET-CHANGE-FROM-OPS> 136822
<EQUALIZATION> (24419)
<DISTRIBUTIONS-OF-INCOME> (301)<F1>
<DISTRIBUTIONS-OF-GAINS> (4472)<F1>
<DISTRIBUTIONS-OTHER> 0
<NUMBER-OF-SHARES-SOLD> 1151<F1>
<NUMBER-OF-SHARES-REDEEMED> (440)<F1>
<SHARES-REINVESTED> 289<F1>
<NET-CHANGE-IN-ASSETS> 45757
<ACCUMULATED-NII-PRIOR> 0
<ACCUMULATED-GAINS-PRIOR> 60308
<OVERDISTRIB-NII-PRIOR> (247)
<OVERDIST-NET-GAINS-PRIOR> 0
<GROSS-ADVISORY-FEES> 180<F1>
<INTEREST-EXPENSE> 0
<GROSS-EXPENSE> 517<F1>
<AVERAGE-NET-ASSETS> 27690<F1>
<PER-SHARE-NAV-BEGIN> 15.88<F1>
<PER-SHARE-NII> .16<F1>
<PER-SHARE-GAIN-APPREC> 2.31<F1>
<PER-SHARE-DIVIDEND> (.17)<F1>
<PER-SHARE-DISTRIBUTIONS> (2.47)<F1>
<RETURNS-OF-CAPITAL> 0<F1>
<PER-SHARE-NAV-END> 15.71<F1>
<EXPENSE-RATIO> 1.87<F1>
<AVG-DEBT-OUTSTANDING> 0
<AVG-DEBT-PER-SHARE> 0
<FN>
<F1>Class B only. All other data are fund level.
</FN>
</TABLE>
<TABLE> <S> <C>
<ARTICLE> 6
<SERIES>
<NUMBER> 004
<NAME> SELIGMAN COMMON STOCK FUND, INC. CLASS D
<MULTIPLIER> 1000
<S> <C>
<PERIOD-TYPE> 12-MOS
<FISCAL-YEAR-END> DEC-31-1998
<PERIOD-END> DEC-31-1998
<INVESTMENTS-AT-COST> 648314
<INVESTMENTS-AT-VALUE> 877273
<RECEIVABLES> 5300
<ASSETS-OTHER> 632
<OTHER-ITEMS-ASSETS> 0
<TOTAL-ASSETS> 883205
<PAYABLE-FOR-SECURITIES> 0
<SENIOR-LONG-TERM-DEBT> 0
<OTHER-ITEMS-LIABILITIES> 2348
<TOTAL-LIABILITIES> 2348
<SENIOR-EQUITY> 0
<PAID-IN-CAPITAL-COMMON> 641391
<SHARES-COMMON-STOCK> 5444<F1>
<SHARES-COMMON-PRIOR> 5092<F1>
<ACCUMULATED-NII-CURRENT> 0
<OVERDISTRIBUTION-NII> (178)
<ACCUMULATED-NET-GAINS> 10685
<OVERDISTRIBUTION-GAINS> 0
<ACCUM-APPREC-OR-DEPREC> 228959
<NET-ASSETS> 85608<F1>
<DIVIDEND-INCOME> 2108<F1>
<INTEREST-INCOME> 246<F1>
<OTHER-INCOME> 2<F1>
<EXPENSES-NET> (1545)<F1>
<NET-INVESTMENT-INCOME> 809<F1>
<REALIZED-GAINS-CURRENT> 103463
<APPREC-INCREASE-CURRENT> 19254
<NET-CHANGE-FROM-OPS> 136822
<EQUALIZATION> (24419)
<DISTRIBUTIONS-OF-INCOME> (851)<F1>
<DISTRIBUTIONS-OF-GAINS> (12435)<F1>
<DISTRIBUTIONS-OTHER> 0
<NUMBER-OF-SHARES-SOLD> 3641<F1>
<NUMBER-OF-SHARES-REDEEMED> (4080)<F1>
<SHARES-REINVESTED> 791<F1>
<NET-CHANGE-IN-ASSETS> 45757
<ACCUMULATED-NII-PRIOR> 0
<ACCUMULATED-GAINS-PRIOR> 60308
<OVERDISTRIB-NII-PRIOR> (247)
<OVERDIST-NET-GAINS-PRIOR> 0
<GROSS-ADVISORY-FEES> 539<F1>
<INTEREST-EXPENSE> 0
<GROSS-EXPENSE> 1545<F1>
<AVERAGE-NET-ASSETS> 82941<F1>
<PER-SHARE-NAV-BEGIN> 15.89<F1>
<PER-SHARE-NII> .16<F1>
<PER-SHARE-GAIN-APPREC> 2.32<F1>
<PER-SHARE-DIVIDEND> (.17)<F1>
<PER-SHARE-DISTRIBUTIONS> (2.47)<F1>
<RETURNS-OF-CAPITAL> 0<F1>
<PER-SHARE-NAV-END> 15.73<F1>
<EXPENSE-RATIO> 1.87<F1>
<AVG-DEBT-OUTSTANDING> 0
<AVG-DEBT-PER-SHARE> 0
<FN>
<F1>Class D only. All other data are fund level.
</FN>
</TABLE>
INDEPENDENT AUDITORS' REPORT
The Board of Directors
Seligman Common Stock Fund, Inc.
In planning and performing our audit of the financial statements of Seligman
Common Stock Fund, Inc. (the "Fund") for the year ended December 31, 1998 (on
which we have issued our report dated January 29, 1999), we considered its
internal control, including control activities for safeguarding securities, in
order to determine our auditing procedures for the purpose of expressing our
opinion on the financial statements and to comply with the requirements of Form
N-SAR, and not to provide assurance on the Fund's internal control.
The management of the Fund is responsible for establishing and maintaining
internal control. In fulfilling this responsibility, estimates and judgments by
management are required to assess the expected benefits and related costs of
controls. Generally, controls that are relevant to an audit pertain to the
entity's objective of preparing financial statements for external purposes that
are fairly presented in conformity with generally accepted accounting
principles. Those controls include the safeguarding of assets against
unauthorized acquisition, use, or disposition.
Because of inherent limitations in any internal control, misstatements due to
error or fraud may occur and not be detected. Also, projections of any
evaluation of internal control to future periods are subject to the risk that
the internal control may be become inadequate because of changes in conditions,
or that the degree of compliance with policies and procedures may deteriorate.
Our consideration of the Fund's internal control would not necessarily disclose
all matters in the internal control that might be material weaknesses under
standards established by the American Institute of Certified Public Accountants.
A material weakness is a condition in which the design or operation of one or
more of the internal control components does not reduce to a relatively low
level the risk that misstatements caused by error or fraud in amounts that would
be material in relation to the financial statements being audited may occur and
not be detected within a timely period by employees in the normal course of
performing their assigned functions. However, we noted no matters involving the
Fund's internal control and its operation, including controls for safeguarding
securities, that we consider to be material weaknesses as defined above as of
December 31, 1998.
This report is intended solely for the information and use of management, the
Board of Directors of Seligman Common Stock Fund, Inc., and the Securities and
Exchange Commission and is not intended to be and should not be used by anyone
other than these specified parties.
/s/ Deloitte & Touche LLP
January 29, 1999
