The comparative analysis between “BIILIS” and “SEPAT” which had a sobering e ffect to Hunan Province was conducted by using the meteorological and hydrograph ic conventional intensive observational data and NECP reanalyzed data. Results s how that the strength and scope of the precipitation brought from Bilis and Sepa t had significant differences. The precipitation of Bilis mainly located in the southeast side of the low pressure circulation and induced the rainstorm in the southeast area of Hunan. The scope of the precipitation of SEPAT was widespread, and the area of heavy precipitation moved from east to west and lasted longer t han Bilis. Further analysis found that the differences between Bills and SEPAT i n moving route, structures and the South China Sea Monsoon intensi ty revealed obvious discrepancy in dynamic structure, distribution of moistureconvergence intensity and vertical movement. These differences are the important reasons that caused different distribution of their heavy rainfall.