method in Yuanjiang According to scarcity of the observed precipitation, this paper proposed a precipitation temporal scale Basin is in the downscaling based on the statistical analysis of the fiver basins of Yuanjiang and Chabagou. The humid zone of the South China, and the Chabagou Basin is in the semi-arid zone of the Northwest China. The proposed method can insure that there is not only an consistency between observed and simulated precipitation data, but also between the rainfall intensities. The application results indicate that this method is simple and practical.