EXHIBIT 11.1   
                                       MASSBANK CORP.                           
                                    Earnings Per Share                          

     The following is a calculation of earnings per share for the three months  
ended March 31, 1999 and 1998.                                                  
                                                                                
                                                           Three Months Ended   
Calculation of Basic                                            March 31,       
  Earnings Per Share                                       1999          1998   
______________________________                          __________   __________ 
                                                                      
Net Income                                              $2,913,000   $2,834,000 
                                                         _________    _________ 
                                                                                
Average common shares outstanding                        3,486,088    3,578,654 
                                                                                
Less:  Unallocated Employee Stock Ownership                                     
       Plan (ESOP) shares not committed                                         
       to be released                                      (35,200)     (44,000)
                                                        __________    _________ 
                                                                                
Weighted average shares outstanding                      3,450,888    3,534,654 
                                                        __________    _________ 
                                                                                
Earnings per share (in dollars)                         $     0.84   $     0.80 
                                                        __________   __________ 
                                                                       
                                                                                
                                                                                
                                                           Three Months Ended   
Calculation of Diluted                                         March 31,        
  Earnings Per Share                                       1999          1998   
______________________________                          __________   __________ 
                                                                      
Net Income                                              $2,913,000   $2,834,000 
                                                        __________   __________ 
                                                                                
Average common shares outstanding                        3,486,088    3,578,654 
                                                                                
Less:  Unallocated Employee Stock Ownership                                     
       Plan (ESOP) shares not committed                                         
       to be released                                      (35,200)     (44,000)
                                                                                
Diluted stsock options                                     116,425      161,930 
                                                        __________   __________ 
                                                                                
Weighted average shares outstanding                      3,567,313    3,696,584 
                                                        __________   __________ 
                                                                                
Earnings per share (in dollars)                         $     0.82   $     0.77 
                                                        __________   __________