Abstract: Amid global changes，China’s vegetation ecosystem has undergone profound transformations. However，there is an urgent need to thoroughly explore the mechanisms underlying the ecological evolution of vegetation in different ecological subregions and historical periods，as well as their differences. Therefore，based on normalized difference vegetation index （NDVI） data，this study investigated the spatiotemporal evolution of vegetation across six major ecological subregions in China and its driving mechanisms using methods such as the gravity center model，lag analysis，geographical detectors，and partial correlation analysis. The results indicate that from 2000 to 2020，mainland China witnessed a decreasing trend in vegetation coverage from east to west. Vegetation coverage increased in all six ecological subregions，with the highest increase （slope of change） observed in the south-central part of China （0.003 9） and the lowest in eastern China （0.002）. From 2000 to 2010，regions with increased vegetation coverage accounted for 92%，and this proportion dropped to 71% from 2010 to 2020. Heterogeneous lag times were observed across different vegetation types in varying regions. Specifically，cultivated vegetation and shrubland generally exhibited a 1 to 3-month lag in response to precipitation；cultivated vegetation and coniferous forests presented a lag limited to the current month in relation to temperature，and broadleaf forests generally displayed a 1 to 2-month lag in response to temperature. Precipitation is identified as the dominant factor driving vegetation changes in North China and the northeastern，northwestern，and southwestern parts of China. In eastern China，land use and gross domestic product （GDP） represent the primary driving force behind vegetation change. In the south-central part of China，both precipitation and land use serve as dominant factors. The results of this study can provide significant data support for vegetation restoration and protection in different ecological regions.