Abstract: Based on the comprehensive and sequential classification system (CSCS) model and geographic information systems approach, a potential natural vegetation (PNV) type map was simulated, and the remaining PNV with their typical area distribution maps in Gannan were made from a combination of land cover data sets from the International Geosphere-Biosphere Programme (IGBP). The monthly and yearly changes of the NDVI (normalized different vegetation index) values in the remaining PNV and their typical areas were analyzed using remote sensing data of MODIS. 1) The remaining PNV distribution covers an area of 33 940 km², accounting for 92.53% of the total land area in Gannan; 2) The typical areas are located in parts of Maqu, Luqu, Diebu Counties, and the northern Xiahe County, while the remainder have a scattered distribution in Zhouqu, Zhuoni, and Lintan Counties; 3) NDVI values of the seven natural vegetation types showed increasing trends with the maximum NDVI values from July to September.