Abstract: With EOF,REOF,the space-time and regional characteristics of the rainy season precipitation in Yunnan were studied by using the precipitation data during the period 1951—2002 from 125 observational stations.The results show:The whole Yunnan will be wet or dry is the main characteristics of rainy season precipitation,but there are the rainfall anomaly differences between in the east and west,and in the southeast and in the northeast.The precipitation abnormal area can be divided into seven sub regions:middle-east,middle-west,northeast,northwest,southeast,and southwest,south part of Yunnan.The precipitation in each region changes with time,in recent 40 years,the precipitation in southeast of Yunnan are decreasing and those over the other sub regions are increasing.