Based on annual precipitation observation data from Wangmuguan and Liyang monitoring stations during the period of 1953 to 2013, the evolution of annual precipitation of Lake Changdanghu in the past 61 years was systematically analyzed by using the methods of Mann-Kendall and Sperman's test, wavelet transform and time series analysis. Results showed that the average annual precipitation is 1115.1 mm in this area. The precipitation presented obviously seasonal dynamics during the whole year. The annual precipitation showed downward trend, and the majority of rainfall occurred in a normal year, the rainy year was nearly the same as the drier year in the last 61 years in Lake Changdanghu. The main period of annual precipitation is 9.5 years at Lake Changdanghu. The conclusion from this paper provided important references for flood control, utilization of water resource, water regulation scheme development and climate change adoption for the Lake Changdanghu.