Climate change and human activities have controlled and influenced all kinds of land surface processes. In order to investigate the impacts of climate change and human activities on regional vegetation dynamics,we combined AVHRR NDVI (1981-2006) and MODIS NDVI (2001-2010) to extract the full time series for vegetation dynamics from 1981-2010 across the Taohe River Basin(TRB). Air temperature and precipitation data from gauge stations during the same period were compiled to regress relationships between climate impacts and vegetation changes,and the Sen's slope was adopted to analyze trend variations in vegetation index and climatic factors. Principal Component Analysis and correlation analysis were used to detect and select key factors with high sensitivity to vegetation dynamics and the regression residual method was used to assess the impacts of human activities on vegetation dynamics. The results suggests that vegetation activity was strengthened across the whole TRB,while the magnitude of increase on the Gannan Plateau (southern Gansu) was higher than on the Loess Plateau,with significant heterogeneity in both time and space. Climate change has led to the variations in the vegetation growing season. There was a very high probability that germination was shifted earlier in both regions,while the withering or dormant season was delayed on the Loess Plateau. On the whole,regional vegetation dynamics in the TRB were due to the combined effects of climate change and human activities. The regression expressions showed good performance with high Nash coefficients and correlation coefficients during calibration and validation. The increase in air temperature contributed more to vegetation change than other climatic factors. Human activities exerted trivial effects on vegetation dynamics,and more than 90% was the result of climate change.