Based on relevant MODIS NDVI data,spatio-temporal variation of the vegetation cover in the Shule River Valley during 2000-2014 was analyzed using the linear trend analysis,M-K test and Hurst index methods,with the aid of ArcGIS and Matlab software. Results show that in the past 15 years,vegetation cover has been increasing rapidly and steadily in the middle and lower reaches of the Shule River Valley,while fluctuating with a mild rising trend in the upper reaches. However,as a whole,it has been improving remarkably in the river valley. The areas with vegetation cover significantly or extra-significantly improved now account for 30.86% of the valley,and are mainly distributed in the irrigated agricultural regions in the middle and lower reaches and mountainous areas with slope less than 20 degree in the upper reaches; while the areas with vegetation cover significantly or extra-significantly degraded do less than 1%,and are concentrated in the regions with natural vegetation cover in the middle and lower reaches of the valley. Since 2004,the valley has been under a relatively warm and humid climate. The total precipitation and mean temperature of the period from June to August affects growth of the vegetation the most significantly in the upper reaches of the valley,showing a significant positive relationship,and that the effect of precipitation is much higher than that of temperature. The vegetation in the middle and lower reaches is not so sensitive to meteorological factors as that in the upper reaches. The areas with vegetation to be improved in future,mostly to be continuously improved,account for 18.63%,and are mainly distributed around the new settlements and in nature reserves in the middle and lower reaches of the Shule River Valley and the west section of the northern piedmont of the Qilian-Altun Mountains,whereas the areas with vegetation degraded amount to 14.25%,and are mostly transformed from areas with vegetation improved and mainly distributed on slopes less than 20 degree in the mountainous areas of Danghenan Mountain,Yema Mountains and Zhaobi Mountain,in the upper reaches of the valley.