Based on the precipitation data from 1953 to 1983, the features of the spatial-temporal distribution of precipitation and regularity of droughts and floods over the Xiuhe River basin in the upper reaches of Zhelin Reservior are analysed. In general, rainfall mainly occurs in the middle and last decade of Jane, Sometimes the rainy season is delayed to the middle decade of July, Statistics show that two month's rainfall from May to June yields about 55% of the year's total. The heavy rainstorms in the end of Meiyu are of great importance for the responsible department to control flood operation. A composite distribution map of 14 heavy rainstorms is given, meanwhile, the features of circulation during drought and flood years are also comparatively investigated in this paper.