WARNING: THE EDGAR SYSTEM ENCOUNTERED ERROR(S) WHILE PROCESSING THIS SCHEDULE.
<TABLE> <S> <C>
<ARTICLE> 6
<CIK> 0000725919
<NAME> ALLIANCE MORTGAGE SECURITIES INCOME FUND, INC.
<SERIES>
<NUMBER> 001
<NAME> ALLIANCE MORTGAGE SECURITIES INCOME FUND, INC.
<S> <C>
<PERIOD-TYPE> 6-MOS
<FISCAL-YEAR-END> DEC-31-2000
<PERIOD-START> JAN-01-2000
<PERIOD-END> JUN-30-2000
<INVESTMENTS-AT-COST> 566,937,402
<INVESTMENTS-AT-VALUE> 557,616,300
<RECEIVABLES> 12,012,897
<ASSETS-OTHER> 139,741
<OTHER-ITEMS-ASSETS> 0
<TOTAL-ASSETS> 569,768,938
<PAYABLE-FOR-SECURITIES> 78,616,380
<SENIOR-LONG-TERM-DEBT> 0
<OTHER-ITEMS-LIABILITIES> 54,730,529
<TOTAL-LIABILITIES> 133,346,909
<SENIOR-EQUITY> 539,043
<PAID-IN-CAPITAL-COMMON> 658,099,453
<SHARES-COMMON-STOCK> 48,970,216
<SHARES-COMMON-PRIOR> 53,201,898
<ACCUMULATED-NII-CURRENT> 565,156
<OVERDISTRIBUTION-NII> 0
<ACCUMULATED-NET-GAINS> (213,460,521)
<OVERDISTRIBUTION-GAINS> 0
<ACCUM-APPREC-OR-DEPREC> (9,321,102)
<NET-ASSETS> 436,422,029
<DIVIDEND-INCOME> 0
<INTEREST-INCOME> 21,732,099
<OTHER-INCOME> 0
<EXPENSES-NET> (5,838,178)
<NET-INVESTMENT-INCOME> 15,893,921
<REALIZED-GAINS-CURRENT> (11,333,411)
<APPREC-INCREASE-CURRENT> 11,583,218
<NET-CHANGE-FROM-OPS> 16,143,728
<EQUALIZATION> 0
<DISTRIBUTIONS-OF-INCOME> (13,866,963)
<DISTRIBUTIONS-OF-GAINS> 0
<DISTRIBUTIONS-OTHER> 0
<NUMBER-OF-SHARES-SOLD> 6,797,982
<NUMBER-OF-SHARES-REDEEMED> (11,900,314)
<SHARES-REINVESTED> 870,650
<NET-CHANGE-IN-ASSETS> (56,833,357)
<ACCUMULATED-NII-PRIOR> 26,366
<ACCUMULATED-GAINS-PRIOR> (202,127,110)
<OVERDISTRIB-NII-PRIOR> 0
<OVERDIST-NET-GAINS-PRIOR> 0
<GROSS-ADVISORY-FEES> 1,266,000
<INTEREST-EXPENSE> 2,764,008
<GROSS-EXPENSE> 5,838,000
<AVERAGE-NET-ASSETS> 410,251,091
<PER-SHARE-NAV-BEGIN> 8.08
<PER-SHARE-NII> 0.28
<PER-SHARE-GAIN-APPREC> 0.01
<PER-SHARE-DIVIDEND> (0.27)
<PER-SHARE-DISTRIBUTIONS> 0
<RETURNS-OF-CAPITAL> 0
<PER-SHARE-NAV-END> 8.10
<EXPENSE-RATIO> 2.47
[AVG-DEBT-OUTSTANDING] 0
[AVG-DEBT-PER-SHARE] 0
</TABLE>
