Topographic variation of vegetation dynamics is critical for understanding the responds of vegetation changes to drivers.Taking satellite-derived normalized difference vegetation index (NDVI) as the proxy of vegetation growth,the trend of vegetation change in 2000-2015 was calculated by using MODIS NDVI data and Mann-kendall method;the topographic variation of vegetation change trend was analyzed with the terrain niche index (TNI) and terrain niche distribution index,and its main driving factors were investigated with forest disturbances,land use and climate data.The results showed that:(1) the grids with an extremely significant decreasing trend of NDVI (Z≤-2.32,P≤0.01) accounted for 3.8% of the study area,and distributed mainly in the northwest,northeast and southeast regions.The grids with an extremely significant increasing trend (Z≥2.32,P≤0.01) accounted for 3.7% of the study area,mainly distributed in the western,southwestern and northeastern regions.(2) Grids of significantly reduced NDVI were dominated by areas with low (1-4) and high (9-12) TNI,while grids of remarkably increased NDVI were dominated by areas with middle TNI (5-8).(3) Inside the regions with significantly decrease NDVI and low TNI,49.2% of the pixels showed sudden change of NDVI change rate,and 33.5% of which was induced by construction and forest degradation.(4) Inside the regions of significantly increased NDVI and middle TNI,the percent of restored after disturbance accounted for 30.7%,mainly due to the significant increase of NDVI caused by ecological restoration.And (5) the 86.2% of pixels with significantly increased NDVI showed no vegetation disturbance,in which the pixels had negative relationship between NDVI and summer temperature accounted for 97% and 96.5% in the east and central geomorphic regions,respectively.To sum up,human activities is the main cause for the significant NDVI decrease in the low terrain niche areas and remarkable NDVI increase in the middle terrain niche region.A significant NDVI decrease in the high terrain niche area may relate to temperature increase in spring and summer.Different vegetation protection methods should be applied according to the level of TNI:the vegetation disturbance caused by human activities should be emphasized in the low TNI area;the effect of ecological engineering and unsuitable land use needs to be paid attention in the middle TNI region to prevent the dual track effect of vegetation restoration and degradation;the response of vegetation to global warming needs to be monitored in high TNI region.