Abstract: The Qinghai-Tibet Plateau has outstanding ecological service value. Due to the volatile climate and fragile environment on Qinghai-Tibet Plateau, it is vulnerable to interference from human activities. Based on the land-use data and an improved equivalent factor method, we quantitatively analyzed the impacts of land-use change on the spatial and temporal variations ofecosystem service values on the Qinghai-Tibet Plateau from 1992-2015. Furthermore, combined with the CA-Markov model, we explored the relationship between land use and ecosystem service value under the scenarios of natural development and ecological protection. From 1992 to 2015, the land-use structure of the Qinghai-Tibet Plateau was stable, with grasslands being the main land use type supplemented by woodlands and bare land. The overall value of ecosystem services showed an increasing trend. Grasslands, water body, and forests were the stable suppliers of ecological value of Qinghai-Tibet Plateau. The spatial distribution of the ecosystem service value of the Qinghai-Tibet Plateau was extremely uneven, while the distribution of different climatic zones was spatially heterogeneous. Cold spots were concentrated in the arid zone of the northwestern Qinghai-Tibet Plateau and the humid zone in the southeast. Hot spots were concentrated in the humid and semihumid zone in the middle. The altitude of 6000 m was the threshold of ecosystem service value of the QinghaiTibet Plateau. The land-use change under the ecological protection scenario is more balanced than that under the natural development scenario. Ecosystem service value generally increases, and the ecological environment develops optimally.

Key words: ecosystem service value, land use change, scenario simulation, Qinghai-Tibet Plateau.