Abstract: Daily precipitation data of 8 stations during the period of 1959-2005 in Mianyang of Sichuan province is used.Empirical orthogonal function and continuous power spectrum method are used to analyze the spatial and temporal distribution and variation tendency of precipitation in Mianyang.The result indicates that the spatial distribution of annual precipitation in Mianyang is not uniform and the local difference is obvious.The spatial distribution can be described as three types:①regional consistent type;②southeast-northwest type;③central type.The annual precipitation shows a decreased tendency all over Mianyang, but the precipitation intensity has increased, and the southeast-northwest type has expanded.The result of power spectrum analysis indicates that the variation of annual precipitation in Mianyang has a significant cycle of 2.9 years and 6.7 years.In addition, annual precipitation and precipitation of different magnitude and days of precipitation at each station in Mianyang also have a declined tendency.However, the characteristics of precipitation and days of precipitation over the storm rainfall of different station are different.The decline tendency of both precipitation and the days of precipitation in wet season is the major cause of the decline tendency of annual precipitation.