The assessment of ecosystem service value in the river section of waterway regulation projects is a crucial indicator for measuring the impact of engineering construction on the sustainable development of ecosystems.Taking the waterway regulation project from Chaotianmen to Fuling in the upper reaches of the Yangtze River as a case study,this research employs land-use changes as a focal point and utilizes the equivalent factor method to assess the ecosystem service value in the pre-construction,mid-construction,and post-construction phases.The results show that the ecosystem service value in Chaofu section decreased by 1.40% from 2015 to 2018 but subsequently increased by 5.73% from 2018 to 2021.Among the twelve service functions,hydrological regulation has the highest proportion,followed by shipping service value,both showing an upward trend before and after the project.Different land types contribute differently to the ecosystem service value,with water bodies consistently being the main contributing and sensitive factors.The research findings can provide theoretical support for promoting the coordinated development of channel construction and ecological protection.