In order to understand the evolution law of precipitation in the desert area of northern Shaanxi, the paper analyzed the basic statistical characteristics of precipitation data at the weather station of Yulin from 1951 to 2013.It used R/S analysis method to analyze the persistence sequence, Kendall rank correlation test to analyzed the trend, the method of power spectrum to analyze the period,and combined the Mann-Kendall and accumulative departure curve method to analyze the mutation.The result showed that the annual precipitation presents the decreasing trend and will continue to decrease and the period is 2.66 years, the notable mutation occurs in end of 1960s.The annual maximum daily precipitation presents an insignificant increasing trend,and the proportion occurred in August is the largest, there is no significant mutation.The cumulative daily precipitation of more than 5mm and less than 10mm present insignificant decreasing trend, the period is 3 years and the significant mutation occurs in early 1970s.The monthly precipitations in January, March, May, June and September present insignificant increasing trend. The precipitations in other months present an insignificant decreasing trend.The mutation analysis of precipitation in flood season from July to October showed that there are no significant mutations in the four months. The precipitation in Yulin station presents a decreasing trend on the whole.