Abstract: Abstract : Objective In order to clarify the driving mechanism of land use expansion in Qaidam Basin, Haixi Mongolian and Tibetan Autonomous Prefecture, Qinghai Province, and predict the future trend of land use change and the spatial and temporal changes of carbon storage in various regions of the study area. Based on the PLUS-InVEST model, according to the land use data of 1980,2000 and 2020, combined with 12 driving factors such as DEM, slope and annual average precipitation, the five main land use expansion driving indexes of cultivated land, grassland, water area, construction land and unused land in the study area were systematically identified, and four different development scenarios of natural development, priority of cultivated land protection, priority of urban development and priority of ecological protection were constructed. The simulation of land use change and spatial-temporal change of carbon storage under multiple scenarios in 2040 was carried out. The results showed that : (1) The main factors for the expansion of cultivated land, grassland, water area, construction land and unused land were soil type ( driving index was 0.18 ), distance from urban main road ( driving index was 0.35 ), annual average precipitation ( driving index was 0.26 ), distance from highway ( driving index was 0.24 ) and distance from urban main road ( driving index was 0.39 ). (2) The predicted area transfer characteristics of different land types under the four development scenarios in 2040 can effectively restrain the disorderly transformation of land, maintain the stability of cultivated land, promote the process of urbanization, and accelerate the restoration and expansion of ecological land.(3)In 2040, only the ecological protection priority scenario increased the total carbon storage in the study area by 2352243.73 t compared with 2020, while the natural development scenario, the cultivated land protection priority scenario, and the urban development priority scenario all decreased, indicating the importance of ecological protection to carbon storage.