Based on the data of 40national meteorological stations in northwest vulnerable ecotone from 1961 to 2015,the characteristics of spatial-temporal variation of precipitation in the past 54years were analyzed by using linear trend estimation,Mann Kendall mutation test,ordinary Kriging interpolation mathematical analysis methods.The results showed that:(1)the precipitation in the 54years decreased in northwest vulnerable ecotone as a whole since the global warming trend was more and more obvious;(2)the spatial variation of annual precipitation reduced roughly from the southeast to northwest,and the tendency rate of annual precipitation reduced gradually at first then increased from the southeast to northwest;(3)the change trend of anomaly in this area from 1961to 2015showed that the precipitation increased in spring,summer and winter, however,it reduced roughly in autumn,and the change rate of precipitation followed the order:winter> spring>autumn>summer,the spatial distribution characteristics of precipitation in the four seasons were obvious,which reduced gradually from the southeast to northwest.