Abstract: Jilin province,in the northeast part of China,is subhumid in climate,and not rich in water resources,with only 1565 m3 year-1 water storage per capita,and water resources are unevenly distributed from region to region with the maximum difference several times as high.The influence of water supplies on agriculture,industry and people's life is discussed at some length in this paper.Analysis reveals that climatic variability shows much more pronounced influence on water storage than on rainfall.A general expression is given:K=(1-B/r)-1,where K is the ratio of relative variation amplitude of water supplies to that of rainfall,B,annual evaporation,r,annual rainfall.Water resources forecasting is also discussed.