<ARTICLE> 5 <CIK> 0000931755 <NAME> AEI INCOME & GROWTH FUND XXI LIMITED PARTNERSHIP <PERIOD-TYPE> 6-MOS <FISCAL-YEAR-END> DEC-31-1998 <PERIOD-END> JUN-30-1998 <CASH> 1,386,877 <SECURITIES> 0 <RECEIVABLES> 0 <ALLOWANCES> 0 <INVENTORY> 0 <CURRENT-ASSETS> 1,386,877 <PP&E> 17,999,697 <DEPRECIATION> (578,427) <TOTAL-ASSETS> 18,808,147 <CURRENT-LIABILITIES> 632,567 <BONDS> 0 <PREFERRED-MANDATORY> 0 <PREFERRED> 0 <COMMON> 0 <OTHER-SE> 18,175,580 <TOTAL-LIABILITY-AND-EQUITY> 18,808,147 <SALES> 0 <TOTAL-REVENUES> 920,787 <CGS> 0 <TOTAL-COSTS> 393,397 <OTHER-EXPENSES> 0 <LOSS-PROVISION> 0 <INTEREST-EXPENSE> 0 <INCOME-PRETAX> 697,327 <INCOME-TAX> 0 <INCOME-CONTINUING> 697,327 <DISCONTINUED> 0 <EXTRAORDINARY> 0 <CHANGES> 0 <NET-INCOME> 697,327 <EPS-PRIMARY> 28.97 <EPS-DILUTED> 28.97