Abstract: Based on the data of MICAPS and rainfall during 1980-2008, by using methods of statistics and synoptic climatological analysis, the main synoptic system of regional heavy rainfall and its Characteristics were analyzed in Dali prefecture.The results show that the main synoptic system giving rise to heavy rainfall weather in Dali prefecture were shear line, Bengal Bay Storm, low vortex, convergence zone of two high-pressure south branch trough, westbound typhoon low-pressure and so on. In this paper, the occurrence frequency and the characteristics of influencing synoptic and their footholds for forecast goal were summed up.