[Objective]The research aimed to understand the role of the physical quantity field forecast data in rainfall forecast.[Method]By comparing rainfall forecast and actual rainfall from July 2 to 3rd,2011 with that from September 12 to 15th,2011 in Yantai,the advantages and disadvantages of different numerical forecast models(Japan fax chart,European center,MM5,Grapes and T639) were contrasted.[Result] MICAPS system could provide the live physical quantity field situation,but not the future evolution situation...