A new drought index, which is based on generalized extreme value (GEV) distribution, was proposed. The GEV index’s theory and method was introduced. By using the monthly precipitation data of 160 sites during 19512010, the drought events calculated and observed are compared and validated. By predicting the drought events occurred during 20092010, the prediction performances of the GEV drought index is validated on monthly scale. The results show that the GEV method has well performances for drought monitoring and prediction, which also has good agreement with CI index, which is widely used for drought monitoring practices. Meanwhile, this drought index can be used for the predication of drought climatology and categorizing of the drought severity. The results also show that the index has good performances in observation sites density regions, but it has some errors in sitesparse regions.