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, 1999 and 1998. Three Months Ended Nine Months Ended Calculation of Basic September 30, September 30, Earnings Per Share 1999 1998 1999 1998 ______________________________ ____ ____ ____ ____ Net Income $2,783,000 $2,695,000 $8,562,000 $8,235,000 _________ _________ _________ _________ Average common shares outstanding 3,387,025 3,592,156 3,429,007 3,587,051 Less: Unallocated Employee Stock Ownership Plan (ESOP) shares not committed to be released (35,200) (44,000) (35,200) (44,000) __________ _________ __________ ________ Weighted average shares outstanding 3,351,825 3,548,156 3,393,807 3,543,051 _________ _________ _________ _________ Earnings per share (in dollars) $ 0.83 $ 0.76 $ 2.52 $ 2.32 _________ _________ _________ _________ Three Months Ended Nine Months Ended Calculation of Diluted September 30, September 30, Earnings Per Share 1999 1998 1999 1998 ______________________________ ____ ____ ____ ____ Net Income $2,783,000 $2,695,000 $8,562,000 $8,235,000 _________ _________ _________ _________ Average common shares outstanding 3,387,025 3,592,156 3,429,007 3,587,051 Less: Unallocated Employee Stock Ownership Plan (ESOP) shares not committed to be released (35,200) (44,000) (35,200) (44,000) Diluted stock options 113,778 144,113 115,332 156,118 _________ _________ _________ _________ Weighted average shares outstanding 3,465,603 3,692,269 3,509,139 3,699,169 _________ _________ __________ _________ Earnings per share (in dollars) $ 0.80 $ 0.73 $ 2.44 $ 2.23 _________ __________ __________ __________