Exhibit 21



MARSHALL & ILSLEY CORPORATION



SUBSIDIARIES



February 28, 2005



|                                                   
|---------------------------------------------------
|Subsidiaries Incorporated or Organized in Wisconsin
|                                                   
|Derivion Corporation                               
|Kirchman Corporation                               
|M&I Bank of Mayville                               
|M&I Marshall & Ilsley Bank                         
|M&I Brokerage Services, Inc.                       
|M&I Capital Markets II, L.L.C.                     
|M&I Community Development Corporation              
|M&I Dealer Finance, Inc.                           
|M&I First National Leasing Corp.                   
|M&I Insurance Services, Inc.                       
|M&I Investment Management Corp.                    
|M&I Investment Partners Management, LLC            
|M&I Mortgage Corp.                                 
|M&I Realty Advisors, Inc.                          
|M&I Support Services Corp.                         
|Metavante Corporation                              
|Milease, LLC                                       
|Printing for Systems, Inc.                         
|Response Data Corp.                                
|Richter-Schroeder Company, Inc.                    



|                                      
|--------------------------------------
|Subsidiaries Incorporated in Arizona  
|                                      
|M&I Insurance Company of Arizona, Inc.



|                                                  
|--------------------------------------------------
|Subsidiaries Incorporated or Organized in Delaware
|                                                  
|Advanced Financial Solutions LLC                  
|Kirchman Company LLC                              
|M&I Capital Markets Group L.L.C.                  
|M&I Capital Trust A                               
|M&I Capital Trust B                               
|M&I Dealer Auto Securitization, LLC               
|M&I Northwoods I LLC                              
|M&I Northwoods II LLC                             
|M&I Northwoods III LLC                            
|M&I Ventures L.L.C.                               
|Metavante Acquisition Company LLC                 
|Metavante Payment Services, LLC                   
|NYCE Corporation                                  
|Prime Associates, Inc.                            
|VECTORsgi, Inc.                                   



|                                      
|--------------------------------------
|Subsidiaries Incorporated in Minnesota
|                                      
|Diversified Business Credit, Inc.     



|                                                  
|--------------------------------------------------
|Subsidiaries Incorporated or Organized in Missouri
|                                                  
|Louisville Realty Company                         
|SWB Holdings, Inc.                                
|SWB Holdings A                                    
|SWB Holdings B                                    
|SWB Holdings C                                    
|SWB Investment II Corporation                     
|Southwest Bank of St. Louis                       



|                                                
|------------------------------------------------
|Subsidiaries Incorporated or Organized in Nevada
|                                                
|M&I Custody of Nevada, Inc.                     
|M&I Marshall & Ilsley Holdings, Inc.            
|M&I Marshall & Ilsley Holdings II, Inc.         
|M&I Marshall & Ilsley Investment Corporation    
|M&I Marshall & Ilsley Investment II Corporation 
|M&I Mortgage Pass-Through Business Trust 2004-1 
|M&I Portfolio Services, Inc.                    
|M&I Servicing Corp.                             
|M&I Zion Holdings, Inc.                         
|M&I Zion Investment Corporation                 
|M&I Zion Investment II Corporation              
|SWB Investment Corporation                      



|                                          
|------------------------------------------
|Subsidiaries Incorporated in New Hampshire
|                                          
|Metavante International, Inc.             



|                                                  
|--------------------------------------------------
|Subsidiaries Incorporated or Organized in Oklahoma
|                                                  
|Advanced Financial Solutions, Inc.                
|CheckClear LLC                                    
|Medical Banking Exchange LLC                      



|                                    
|------------------------------------
|Subsidiaries Incorporated in Vermont
|                                    
|M&I Mortgage Reinsurance Corporation



|                                                          
|----------------------------------------------------------
|Subsidiaries Organized Under the Laws of the United States
|                                                          
|M&I Bank FSB                                              
|Marshall & Ilsley Trust Company National Association      



|                                               
|-----------------------------------------------
|Subsidiaries Organized Under the Laws of Canada
|                                               
|Everlink Payment Services, Inc.                
|Metavante Canada Corporation