Abstract: This study focuses on the main urban area of Lanzhou and analyzes the impact on Ecosystem Services Value （ESV） of land use changes from 1985 to 2022. By using the land use transfer matrix and the ecosystem service value equivalent factor method, combined with long-term sequence of land use data, the impact of land use type changes on ecosystem service value was quantitatively evaluated. The findings are as follows: The land use types in the main urban area of Lanzhou have undergone significant changes in the past 38 years, with areas of grassland and cultivated land decreasing, while forest land, construction land, water bodies, and unused land areas have increased. The total ecosystem service value has shown a trend of first increasing and then decreasing. Grassland, cultivated land, and forest land are the main contributors to ecosystem services, while the expansion of construction land has had a significant negative impact on ecosystem services value. Provisioning services, regulating services, supporting services, and cultural services have shown different trends in various time periods. Provisioning and regulating services peaked in 2015 and declined thereafter, while changes in supporting and cultural services were relatively small. There are significant differences in the contribution rates of different land use types to changes in ecosystem services value, with grassland having the highest average contribution rate （52.83%）, followed by cultivated land （19.64%） and water bodies （17.23%）. The results provide scientific guidance for future land use planning and ecological protection in Lanzhou, recommending enhanced protection of grasslands and cultivated land during urbanization, along with reasonable planning of construction land expansion to maintain the health and sustainable development of regional ecosystems.