The climatic tendency of warming and drying since the beginning of this century has been shown distinctly in the mid-latitude zone of the North Hemisphere. It is of a series of impacts on the water resources system.especially in the arid or semi-arid regions. On the basis of this fact,the inland-lake changes in response to the climatic fluctuation are investigated. The comprehensive study shows that the general trend of the inland lake may be shrunk under warm and dry conditions. Further research of the impact of the changes in precipitation and temperature on the lake has been carried out,showing that the rise of temperature may cause an increase of the evaporation and runoff supplied by melting glacier,and that a decrease of precipitation may lead to reduction of the runoff and shrinkage of the lake area. Qinghai Lake is a typieal one which represents the lake evolution dominated by precipitation as well as Lake Issuk-kul dominated by temperature.