Abstract: Tibet Plateau is one of the most serious areas in the occurrence and development of desertification in China, therefore, it is significant to monitor and prevent the desertifiactiion.This paper is based on the time sequence images of MODIS-NDVI, with DEM data and vector data of the 1:4000000 scale land, it used vegetation coverage division processing and supervised classification method to extract desertification of Tibet Plateau to get the desertification degree and distribution in Tibet Plateau.The result shows that:the desertification area is 227034.65 km2, accounted for 18.91% of the total land area.The desertification degree is primarily mild and moderate and the desertification mainly distributed in Ali, Naqu and Rikaze area.