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000 A000000 06/30/98
000 C000000 014358
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001 A000000 SELIGMAN COMMON STOCK FUND, INC.
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011 A000001 SELIGMAN FINANCIAL SERVICES, INC.
011 B000001 8-25845
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012 B000001 84-1895
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013 A000001 DELOITTE & TOUCHE LLP
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<PAGE> PAGE 2
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013 B030001 10281
014 A000001 SELIGMAN SERVICES, INC.
014 B000001 8-47717
015 A000001 INVESTORS FIDUCIARY TRUST CO.
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020 B000002 13-3364318
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020 A000008 GOLDMAN SACHS & CO.
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020 A000009 EDWARDS (A.G.) & SONS, INC.
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020 A000010 BRIDGE TRADING COMPANY
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<PAGE> PAGE 3
021 000000 941
022 A000001 UBS-GRAND CAYMAN
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022 C000002 993315
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022 A000003 REPUBLIC NATIONAL BK OF NEW YORK-GRAND CAYMAN
022 B000003 13-2774726
022 C000003 942820
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<PAGE> PAGE 5
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<PAGE> PAGE 6
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<PAGE> PAGE 7
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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> 6-MOS
<FISCAL-YEAR-END> DEC-31-1998
<PERIOD-END> JUN-30-1998
<INVESTMENTS-AT-COST> 692541
<INVESTMENTS-AT-VALUE> 891207
<RECEIVABLES> 3968
<ASSETS-OTHER> 434
<OTHER-ITEMS-ASSETS> 0
<TOTAL-ASSETS> 895609
<PAYABLE-FOR-SECURITIES> 4671
<SENIOR-LONG-TERM-DEBT> 0
<OTHER-ITEMS-LIABILITIES> 4752
<TOTAL-LIABILITIES> 9423
<SENIOR-EQUITY> 0
<PAID-IN-CAPITAL-COMMON> 592747
<SHARES-COMMON-STOCK> 47189<F1>
<SHARES-COMMON-PRIOR> 46135<F1>
<ACCUMULATED-NII-CURRENT> (904)
<OVERDISTRIBUTION-NII> 0
<ACCUMULATED-NET-GAINS> 95678
<OVERDISTRIBUTION-GAINS> 0
<ACCUM-APPREC-OR-DEPREC> 198665
<NET-ASSETS> 771919<F1>
<DIVIDEND-INCOME> 8375<F1>
<INTEREST-INCOME> 1334<F1>
<OTHER-INCOME> 19<F1>
<EXPENSES-NET> (4205)<F1>
<NET-INVESTMENT-INCOME> 5523<F1>
<REALIZED-GAINS-CURRENT> 96411
<APPREC-INCREASE-CURRENT> (11040)
<NET-CHANGE-FROM-OPS> 91267
<EQUALIZATION> 0
<DISTRIBUTIONS-OF-INCOME> (6325)<F1>
<DISTRIBUTIONS-OF-GAINS> (52971)<F1>
<DISTRIBUTIONS-OTHER> 0
<NUMBER-OF-SHARES-SOLD> 3923<F1>
<NUMBER-OF-SHARES-REDEEMED> (5426)<F1>
<SHARES-REINVESTED> 2557<F1>
<NET-CHANGE-IN-ASSETS> 51086
<ACCUMULATED-NII-PRIOR> 21
<ACCUMULATED-GAINS-PRIOR> 60040
<OVERDISTRIB-NII-PRIOR> 0
<OVERDIST-NET-GAINS-PRIOR> 0
<GROSS-ADVISORY-FEES> 2490<F1>
<INTEREST-EXPENSE> 0
<GROSS-EXPENSE> 4205<F1>
<AVERAGE-NET-ASSETS> 772567<F1>
<PER-SHARE-NAV-BEGIN> 15.92<F1>
<PER-SHARE-NII> 0.12<F1>
<PER-SHARE-GAIN-APPREC> 1.64<F1>
<PER-SHARE-DIVIDEND> (0.14)<F1>
<PER-SHARE-DISTRIBUTIONS> (1.18)<F1>
<RETURNS-OF-CAPITAL> 0<F1>
<PER-SHARE-NAV-END> 16.36<F1>
<EXPENSE-RATIO> 1.10<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> 6-MOS
<FISCAL-YEAR-END> DEC-31-1998
<PERIOD-END> JUN-30-1998
<INVESTMENTS-AT-COST> 692541
<INVESTMENTS-AT-VALUE> 891207
<RECEIVABLES> 3968
<ASSETS-OTHER> 434
<OTHER-ITEMS-ASSETS> 0
<TOTAL-ASSETS> 895609
<PAYABLE-FOR-SECURITIES> 4671
<SENIOR-LONG-TERM-DEBT> 0
<OTHER-ITEMS-LIABILITIES> 4752
<TOTAL-LIABILITIES> 9423
<SENIOR-EQUITY> 0
<PAID-IN-CAPITAL-COMMON> 592747
<SHARES-COMMON-STOCK> 1758<F1>
<SHARES-COMMON-PRIOR> 1232<F1>
<ACCUMULATED-NII-CURRENT> (904)
<OVERDISTRIBUTION-NII> 0
<ACCUMULATED-NET-GAINS> 95678
<OVERDISTRIBUTION-GAINS> 0
<ACCUM-APPREC-OR-DEPREC> 198665
<NET-ASSETS> 28678<F1>
<DIVIDEND-INCOME> 273<F1>
<INTEREST-INCOME> 45<F1>
<OTHER-INCOME> 1<F1>
<EXPENSES-NET> (232)<F1>
<NET-INVESTMENT-INCOME> 87<F1>
<REALIZED-GAINS-CURRENT> 96411
<APPREC-INCREASE-CURRENT> (11040)
<NET-CHANGE-FROM-OPS> 91267
<EQUALIZATION> 0
<DISTRIBUTIONS-OF-INCOME> (118)<F1>
<DISTRIBUTIONS-OF-GAINS> (1920)<F1>
<DISTRIBUTIONS-OTHER> 0
<NUMBER-OF-SHARES-SOLD> 600<F1>
<NUMBER-OF-SHARES-REDEEMED> (193)<F1>
<SHARES-REINVESTED> 119<F1>
<NET-CHANGE-IN-ASSETS> 51086
<ACCUMULATED-NII-PRIOR> 21
<ACCUMULATED-GAINS-PRIOR> 60040
<OVERDISTRIB-NII-PRIOR> 0
<OVERDIST-NET-GAINS-PRIOR> 0
<GROSS-ADVISORY-FEES> 81<F1>
<INTEREST-EXPENSE> 0
<GROSS-EXPENSE> 232<F1>
<AVERAGE-NET-ASSETS> 25159<F1>
<PER-SHARE-NAV-BEGIN> 15.88<F1>
<PER-SHARE-NII> 0.06<F1>
<PER-SHARE-GAIN-APPREC> 1.63<F1>
<PER-SHARE-DIVIDEND> (0.08)<F1>
<PER-SHARE-DISTRIBUTIONS> (1.18)<F1>
<RETURNS-OF-CAPITAL> 0<F1>
<PER-SHARE-NAV-END> 16.31<F1>
<EXPENSE-RATIO> 1.86<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> 6-MOS
<FISCAL-YEAR-END> DEC-31-1998
<PERIOD-END> JUN-30-1998
<INVESTMENTS-AT-COST> 692541
<INVESTMENTS-AT-VALUE> 891207
<RECEIVABLES> 3968
<ASSETS-OTHER> 434
<OTHER-ITEMS-ASSETS> 0
<TOTAL-ASSETS> 895609
<PAYABLE-FOR-SECURITIES> 4671
<SENIOR-LONG-TERM-DEBT> 0
<OTHER-ITEMS-LIABILITIES> 4752
<TOTAL-LIABILITIES> 9423
<SENIOR-EQUITY> 0
<PAID-IN-CAPITAL-COMMON> 592747
<SHARES-COMMON-STOCK> 5245<F1>
<SHARES-COMMON-PRIOR> 5092<F1>
<ACCUMULATED-NII-CURRENT> (904)
<OVERDISTRIBUTION-NII> 0
<ACCUMULATED-NET-GAINS> 95678
<OVERDISTRIBUTION-GAINS> 0
<ACCUM-APPREC-OR-DEPREC> 198665
<NET-ASSETS> 85589<F1>
<DIVIDEND-INCOME> 917<F1>
<INTEREST-INCOME> 144<F1>
<OTHER-INCOME> 2<F1>
<EXPENSES-NET> (777)<F1>
<NET-INVESTMENT-INCOME> 286<F1>
<REALIZED-GAINS-CURRENT> 96411
<APPREC-INCREASE-CURRENT> (11040)
<NET-CHANGE-FROM-OPS> 91267
<EQUALIZATION> 0
<DISTRIBUTIONS-OF-INCOME> (378)<F1>
<DISTRIBUTIONS-OF-GAINS> (5882)<F1>
<DISTRIBUTIONS-OTHER> 0
<NUMBER-OF-SHARES-SOLD> 1236<F1>
<NUMBER-OF-SHARES-REDEEMED> (1442)<F1>
<SHARES-REINVESTED> 359<F1>
<NET-CHANGE-IN-ASSETS> 551086
<ACCUMULATED-NII-PRIOR> 21
<ACCUMULATED-GAINS-PRIOR> 60040
<OVERDISTRIB-NII-PRIOR> 0
<OVERDIST-NET-GAINS-PRIOR> 0
<GROSS-ADVISORY-FEES> 272<F1>
<INTEREST-EXPENSE> 0
<GROSS-EXPENSE> 777<F1>
<AVERAGE-NET-ASSETS> 84420<F1>
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<FN>
<F1>Class D only. All other data are fund level.
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</TABLE>