EXHIBIT 11.1 MASSBANK CORP. Earnings Per Share The following is a calculation of earnings per share for the three and and nine months ended September 30, 1998 and 1997. Three Months Ended Nine Months Ended Calculation of Basic September 30, September 30, Earnings Per Share 1998 1997 1998 1997 ______________________________ ____ ____ ____ ____ Net Income $2,695,000 $2,589,000 $8,235,000 $7,511,000 _________ _________ _________ _________ Average common shares outstanding 3,592,156 3,572,418 3,587,051 3,578,807 Less: Unallocated Employee Stock Ownership Plan (ESOP) shares not committed to be released (44,000) (52,800) (44,000) (52,800) __________ _________ __________ ________ Weighted average shares outstanding 3,548,156 3,519,618 3,543,051 3,526,007 _________ _________ _________ _________ Earnings per share (in dollars) $ 0.76 $ 0.74 $ 2.32 $ 2.13 _________ _________ _________ _________ Three Months Ended Nine Months Ended Calculation of Diluted September 30, September 30, Earnings Per Share 1998 1997 1998 1997 ______________________________ ____ ____ ____ ____ Net Income $2,695,000 $2,589,000 $8,235,000 $7,511,000 _________ _________ _________ _________ Average common shares outstanding 3,592,156 3,572,418 3,587,051 3,578,807 Less: Unallocated Employee Stock Ownership Plan (ESOP) shares not committed to be released (44,000) (52,800) (44,000) (52,800) Diluted stock options 144,113 150,952 156,118 130,747 _________ _________ _________ _______ Weighted average shares outstanding 3,692,269 3,670,570 3,699,169 3,656,754 _________ _________ _________ _________ Earnings per share (in dollars) $ 0.73 $ 0.70 $ 2.23 $ 2.05 _________ __________ __________ __________