【Objective】The study of the relationship between vegetation cover change and precipitation is greatly significant in analyzing the response of vegetation ecosystem to the change of precipitation caused by climate warming.【Method】This paper analyzed the spatial and temporal trends of NDVI and precipitation by TRMM with the data in Tory County from 2011 to 2015,achieve smooth movement between precipitation and NDVI data,and discussed the dynamic changes of NDVI and precipitation by TRMM and the correlation between NDVI and precipitation. 【Result】(i) The trend of NDVI and precipitation TRMM were complementar, and by the perspective of spatial distribution characteristics, the spatial distribution of NDVI tends to be similar to precipitation during the same period or the previous period. The dynamic changes of NDVI cannot be fully explained,because the impact factors of NDVI and the precipitation were numerous; (ii) From the time point of view,the gradient relation between the precipitation and the NDVI by time,and the NDVI gradually increases after the precipitation. It proves that the precipitation has a typical hysteresis effect on NDVI by spatial distribution characteristics and temporal variation characteristics; (iii) The correlation between NDVI and precipitation by TRMM is significantly positive correlation in 5 years,precipitation by TRMM can promote the increase of NDVI.【Conclusion】Precipitation has a significant driving effect on vegetation growth,the vegetation cover will change characteristics gradually with the precipitation.