Based on the observational data of precipitation in 11meteorological stations from 1951to 2010in forest region of Inner Mongolia Daxing′anling,we used a linear regression,accumulative anomaly method, Mann Kendall test(Mann-Kendall)method and Morlet wavelet analysis method to analyze the annual precipitation changes in forest region of Inner Mongolia Daxing′anling in recent 40years and to reveal the variation characteristics of annual precipitation under the climate warming background.The results showed as follows: precipitation in forest region of Inner Mongolia Daxing′anling showed a slight downward with fluctuation,the trend tendency rate was-7.4mm/decade,inter annual variation precipitation was significant,precipitation of climate trend rate had very obvious regional features,which experienced the wetdrywetdry process;the time of precipitation mutation occurred roughly from 1975to 1979and in 1999based on the cumulative distance average analysis and Mann Kendall(Mann-Kendall)test method.Morlet wavelet analysis results showed that annual precipitation in recent 40years in Daxing′anling forest region of Inner Mongolia contained a number of periods with different time scales,the 27-year periodic oscillation was the strongest,and had the most significant effect on precipitation,and high precipitation period will occur in the years 2014to 2020.