To reveal the spatiotemporal variability of terrestrial ecosystem sensitivity on the Qinghai-Tibet Plateau, the spatial distribution of the ecosystem sensitivity and the climate factors to dominate vegetation growth on the Qinghai-Tibet Plateau from 2000 to 2021 were explored. To this end, Vegetation Sensitivity Index (VSI) was applied to the MODIS EVI and ERA5 reanalysis data including temperature, precipitation, and solar radiation. The timeframe of this study was restricted to the growing season with months from June to August. Moreover, the temporal variability of VSI was investigated for the period of P₁(2000-2006), P₂(2007-2013), and P₃(2014-2021), respectively. Results indicate that:(1) the spatial heterogeneity of VSI in growing season was strong on the QTP from 2000 to 2021. High VSI values were observed in shrubs and forests located in the southeastern Qinghai-Tibet Plateau. By contrast, low VSI values were found in alpine deserts, alpine grasslands, and alpine meadows grown in the northwestern Qinghai-Tibet Plateau. (2) During the whole investigation period, temperature, precipitation, and solar radiation dominated the VSI variation in 55.89%, 19.24%, and 24.87% of the Qinghai-Tibet Plateau, respectively. Specifically, temperature dominated the VSI of shrubs and forests in the southeast Qinghai-Tibet Plateau and precipitation controlled the VSI in most alpine meadows of the northeastern Qinghai-Tibet Plateau. Solar radiation regulated the VSI in most of alpine grasslands distributed in the southwestern Qinghai-Tibet Plateau. Temporal variability results show that:(3) During the periods of P₁, P₂, and P₃, the VSI increased and decreased continuously in 18.39% and 10.09% pixels, respectively. The VSI of alpine desert, alpine grassland, and alpine meadow remained unchange during the P₁-P₂ period while showed an increasing trend during the P₂-P₃ period. By contrast, the VSI of shrubs and forests displayed an increasing (P₁-P₂) and then a decreasing (P₂-P₃) trend. (4) A strong spatiotemporal heterogeneity of the VSI on the Qinghai-Tibet Plateau was observed in the three periods. The proportion of pixels where temperature dominated the vegetation growth in the three periods had a slight change during P₁-P₂ but was reduced in P₃, corresponding proportion values were P₁(58.15%), P₂(61.34%), and P₃(49.47%), respectively. Conversely, the proportion of pixels that precipitation played a dominate role increased from 18.57% (P₁) and 18.47% (P₂) to 26.64% (P₃). For solar radiation, the associated proportion values had a small fluctuation during the three periods. Overall, the responses of alpine grassland and alpine meadow ecosystems to climate change on the Qinghai-Tibet Plateau were increasing. The risk of grassland degradation on the Qinghai-Tibet Plateau might exacerbate due to the climate change with a large variability on the Qinghai-Tibet Plateau. This study aims to provide a reference for the dynamic assessment of ecosystem sensitivity on the Qinghai-Tibet Plateau in the context of global climate change.