Based on the 1971-2000 monthly precipitation data observed at 34meteorological stations in the Chongqing region and the 100m×100m DEM(Digital Elevation Model)of Chongqing,the spatial distribution of precipitation of Chongqing was studied.In light of the principles ofmountain climatology and using GIS(Geographical Information Systems)technology,the factors affecting the spatial distribution of precipitation were analyzed,themodel to simulate the spatial distribution of averagedmonthly precipitation was established,and the spatial distribution of averagedmonthly precipitation was computed.The results show that the precipitation increased with the elevation,and themaximum value ofmonthly precipitation appeared in the northeastmountainous region;and the seasonal change of precipitation in Chongqing was distinctive.