EXHIBIT 11.1 MASSBANK CORP. Earnings Per Share The following is a calculation of earnings per share for the three months ended March 31, 2000 and 1999. Three Months Ended Calculation of Basic March 31, Earnings Per Share 2000 1999 ______________________________ __________ __________ Income $2,828,000 $2,913,000 _________ _________ Average common shares outstanding 3,289,524 3,486,088 Less: Unallocated Employee Stock Ownership Plan (ESOP) shares not committed to be released (26,400) (35,200) __________ _________ Weighted average shares outstanding 3,263,124 3,450,888 __________ _________ Earnings per share (in dollars) $ 0.87 $ 0.84 __________ __________ Three Months Ended Calculation of Diluted March 31, Earnings Per Share 2000 1999 ______________________________ __________ __________ Net Income $2,828,000 $2,913,000 __________ __________ Average common shares outstanding 3,289,524 3,486,088 Less: Unallocated Employee Stock Ownership Plan (ESOP) shares not committed to be released (26,400) (35,200) Diluted stock options 74,235 116,425 __________ __________ Weighted average shares outstanding 3,337,359 3,567,313 __________ __________ Earnings per share (in dollars) $ 0.85 $ 0.82 __________ __________