Abstract: The correlation coefficients between the sea surface temperature and the May rainfall of Yunnan,between that and the May rainfall of East Yunnan,and between that and the May rainfall of West Yunnan were calculated and analyzed with the global sea surface temperature data provided by NCC/NCAR and the May rainfall data of Yunnan.The results indicated that,there is stronger temporal and spattal correlation between them.The(’-+-+’)pattern between sea surface temperature in previous November and May the rainfall in may is the same as that between current sea surface temperature and the rainfall in May.The sea surface temperature over north Indian Ocean significantly impacts on May rainfall of East Yunnan,while that over North Atlantic significantly impacts on the May rainfall of West Yunnan.The correlation between the May rainfall of East Yunnan and the sea is stronger than that that between the May rainfall of West Yunnan and the sea surface temperature,in which the most difference appears on popical Pacific.The May raifall of Yunnan may be forecasted easted with the sea surface temperature over South Atlantic.