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