Using the MODIS NDVI data from 2000 to 2011 in Xinjiang region, the desertification variation was monitored, and the response of desertification to climate change was analyzed, then the reason of desertification was surveyed. The results indicated that the desertification was controlled in Xinjiang region in the recent ten years, but in some areas it was continually worsen. The response of desertification to annual precipitation was dramatically, especially in the northern of Xinjiang region. The most serious area of desertification in Xinjiang region was located in the middle and lower reaches of rivers in the Tarim Basin. The degenerated ecosystem mainly was the meadow ecosystem, and the cause of desertification was mainly the spatial change of the water resources utilization, especially the change of groundwater water level.