Using the data of monthly precipitation in China,sea surface temperatures and the general circulation indexes,the general circulation feature,climate background and SST influence were studied.It′s shown that:there is an apparent teleconnection between the general circulation indexes and SST field in the Pacific; the variation of the Pacific SST in winter and spring is able to predict precipitation tread in South China in next summer.Floods in South China were formed in this kind of circulation background,the early change of SST and feature of general circulation have an indication to precipitation forecast in South China.