<ARTICLE> 9 <CIK> 0000799166 <NAME> MASSBANK CORP. <MULTIPLIER> 1,000 <PERIOD-TYPE> 12-MOS <FISCAL-YEAR-END> DEC-31-1997 <PERIOD-START> JAN-01-1997 <PERIOD-END> DEC-31-1997 <CASH> 6,808 <INT-BEARING-DEPOSITS> 2,083 <FED-FUNDS-SOLD> 105,241 <TRADING-ASSETS> 21,260 <INVESTMENTS-HELD-FOR-SALE> 482,224 <INVESTMENTS-CARRYING> 372 <INVESTMENTS-MARKET> 372 <LOANS> 272,303 <ALLOWANCE> (2,334) <TOTAL-ASSETS> 925,403 <DEPOSITS> 809,850 <SHORT-TERM> 1,502 <LIABILITIES-OTHER> 9,491 <LONG-TERM> 781 <PREFERRED-MANDATORY> 0 <PREFERRED> 0 <COMMON> 7,337 <OTHER-SE> 96,442 <TOTAL-LIABILITIES-AND-EQUITY> 925,403 <INTEREST-LOAN> 19,928 <INTEREST-INVEST> 33,488 <INTEREST-OTHER> 7,317 <INTEREST-TOTAL> 60,733 <INTEREST-DEPOSIT> 34,681 <INTEREST-EXPENSE> 34,681 <INTEREST-INCOME-NET> 26,052 <LOAN-LOSSES> 260 <SECURITIES-GAINS> 1,939 <EXPENSE-OTHER> 13,425 <INCOME-PRETAX> 16,165 <INCOME-PRE-EXTRAORDINARY> 16,165 <EXTRAORDINARY> 0 <CHANGES> 0 <NET-INCOME> 10,167 <EPS-PRIMARY> 2.88 <EPS-DILUTED> 2.77 <YIELD-ACTUAL> 2.93 <LOANS-NON> 1,771 <LOANS-PAST> 0 <LOANS-TROUBLED> 0 <LOANS-PROBLEM> 1,771 <ALLOWANCE-OPEN> 2,237 <CHARGE-OFFS> (327) <RECOVERIES> 59 <ALLOWANCE-CLOSE> 2,334 <ALLOWANCE-DOMESTIC> 1,716 <ALLOWANCE-FOREIGN> 0 <ALLOWANCE-UNALLOCATED> 618