Abstract: Phenology reflects the responses of ecosystem to climate change, and is considered as a major indicator of terrestrial ecosystem changes. As one of the most important phenological indicators, the trend of green-up dates（GUD） has an important impact on the water and carbon processes of the ecosystem. A number of studies have shown that the change direction and amplitude of green-up dates（GUD） depend on the climatic conditions of the region. The upper Minjiang River（UMR） is a typical mountainous watershed in southwest China, where vegetation has a vertical distribution pattern,and climate has a warming-drying trend. In this study, based on the MCD12Q2 products, the green-up dynamics of the major three vegetation types in UMR from 2001 to 2016 and its driving factors are analyzed by tendency test and or relation analysis. The results show that the average GUD are DOY 124.5±12.5, 105.0±14.5 and 113.2±10.5 for grass land（GL）, mixed forest（MF） and deciduous broadleaved forest（DBF）. The vertical distribution of the average GUD in UMR has obvious altitude differences. The average GUD has increasing trends with altitude for the three vegetation types. The GUD shows significantly decreasing trends（p＜0.05） for both GL and DBF, and insignificant decreasing trend（p＞ 0.05） for MF. The altitude boundary line of 3 500 m is found for the GUD trend distribution, above which the advancing rates of GUD are significant and higher. The advances of the GUD for the three vegetation types in the UMR during 2001-2016 mainly results from the warmer and drier spring climate, and the minimum temperature and precipitation in March and April are main driving factors. The research findings can serve a further research on the ecological process of ecosystem in UMR.