[Objective] The spatiotemporal evolution patterns of ecological environment quality and its main driving factors in Qinghai Province from 2000 to 2024 were systematically revealed， in order to provide a scientific basis for the formulation of ecological protection measures and restoration strategies in this region. [Methods] Based on moderate resolution imaging spectroradiometer （MODIS） remote sensing data， the salinity index （SI₃） was incorporated into the remote sensing ecological index （RSEI）， and a modified remote sensing ecological index （mRSEI） was then constructed using a full time-series normalization method. Ecological function zones were used as the analysis units， and methods such as the Geodetector and trend analysis were employed. [Results] ① From 2000 to 2024， the overall ecological environment quality of Qinghai Province showed a slow upward trend， with an average increase of 0.025/10 a. Except for the alpine desert grassland ecological zone in the northern Tibetan Plateau， the average mRSEI values of all ecological function zones increased to varying degrees. ② The overall ecological environment quality of Qinghai Province was at a medium level （mRSEI=0.45）， with significant differences observed among different ecological zones. Among them， the forest and alpine grassland ecological zones in Qilian Mountains exhibited relatively better ecological quality （mRSEI=0.60）， whereas the desert ecological zone of the Qaidam Basin showed poor ecological conditions （mRSEI=0.22）. ③ The driving factors of ecological environment quality differed significantly across different ecological zones. For example， the main driving factors of forest and alpine grassland ecological zones in Qilian Mountains were gross primary productivity （q=0.61）， soil moisture （q=0.51）， and annual precipitation （q=0.44）， while the alpine desert grassland ecological zone in northern Tibetan Plateau was mainly driven by soil moisture （q=0.59）. [Conclusion] In general， the ecological environment of Qinghai Province shows an improving trend， however the ecological conditions and driving mechanisms differ significantly across different ecological function zones.