Abstract: Based on the MODIS standard vegetation index products (NDVI ) and the average temperature and precipitation data of 9 meteorological sites in the study area from 2000 to 2016, the authors adopted the methods of Slope trend analysis and correlation analysis by using the Yarlung Zangbo River, Nyangqu River and Lhasa River region (the YNL River region) of Tibet as a case, to analyze the characteristics of vegetation change and its main climatic driving factors, which could provide scientific data support for ecological protection, restoration and afforestation in this area. The results showed that: (1) since 2000, theNDVI in the YNL River region of Tibet decreased with fluctuation, among which the vegetation along the river valley increased; (2) the trend of climate change in the study area was becoming warmer and drier; (3) at different time scales, the correlation of vegetation variation with average temperature and precipitation was significant, the annual maximumNDVI was positively correlated with annual total precipitation, and negatively correlated with annual mean temperature; on the monthly scale: the maximum monthly NDVI showed a significant positive correlation with the monthly average temperature and the total monthly precipitation, and the correlation coefficient with precipitation was obviously higher than that with the temperature. Therefore, precipitation is the main factor affecting vegetation changes in the YNL River region of Tibet.