The Standardized Precipitation Evapotranspiration Index (SPEI) is an ideal indicator for the drought evolution trend. Based on the monthly mean surface air temperature and monthly precipitation at 160 meteorological stations over China from 1951 to 2009, spatial distribution of drought trends, the seasonal trends and the extreme event frequency of droughts were analyzed by using the SPEI. The results showed that the drying trend almost occurs in the whole of China. The most significant drought occurs in the west, north, and northeast China, while it becomes wet in some regions of the northern of Xinjiang and Sichuan-Yunnan. The drying trend occurs during all four seasons, especially in spring and autumn. The summer is always in the dry state in the last 15 years, but the drying trend in summer is not significant at the 0.05 level. In addition, the frequency of extreme drought has increased significantly, which will probably hinder China's economy development.