The knowledge of vegetation cover changes will provide considerable insights into the dynamic process of desertification.The study illustrated the vegetation dynamic changes in Dulan County,Qinghai Province using 2000—2009MODIS NDVI data,and on this basis,the relationship between NDVI changes with temperature and rainfall variations were investigated,providing the basic data to land use planning in alpine areas and desertification prevention and control.The results indicate that the NDVI values of the area presented a slow ascendant trend from 2000to 2009,at the rate of 0.002 9/a.The NDVI values had a strong seasonal changes in a year,but the overall NDVIs were not high for the county,with the maximum value of 0.22.The vegetation condition were improved significantly in 39.71%of the area of the entire county,which mainly located in basins of Chacha river and Chahanwusu river and a large area of Qaidam river downstream.However,the vegetation degeneration was found in the upper and middle reaches of Qaidam river,accounting for 17.74%of the entire county,suggesting that the desertification control should be further strengthened.The temperature and rainfall were the two main natural factors influencing the NDVI dynamics of the county;the NDVIs correlated strongly significantly with the temperature(p< 0.01),and significantly with the rainfall amount(p<0.05)from May to September annually.The impact of the temperature on the NDVI was stronger than that of the precipitation