Abstract: Relief degree of ground surface (RDGS) is closely related to magnitude of the ground surface and hence to land use patterns, which consequently affects service value of the ecosystem in the region. The objective of the study is to examine effect of RDGS on ecosystem service value in the Chongqing Section of the Three Gorges Reservoir Region, China. The ASTER GDEM V2 dataset was used to extract RDGS of the region by means of window analysis. Based on the land use data available, ecosystem service value in the section was worked out using Costanza's method and the modified ecosystem service value coefficients. Then correlation between the RDGS and land ecosystem services value was quantitatively analyzed. Results show that:(1) The landform is complicated and the RDGS varies sharply in the region. As a whole, RDGS is higher in the east than that in the west, and the highest in Wuxi (1.360 3),and the lowest in Yuzhong(0.289 0). (2) Per capita ecosystem service value distributed unevenly in space. The value is high in the eastern part, for it is composed of natural forest reserves and water conservation and low in the western part, for it consists mainly of key development zones of cities and new urban development areas. (3) A positive relationship is observed between RDGS and per capita ecosystem service values. In terms of effect of RDGS on ecosystem service values, the services display a decreasing order of raw material production >food production >gas regulation >climate regulation >total value >hydrological regulation >soil conservation >provision of aesthetic landscape >maintenance of biodiversity >waste disposal. The study reveals that strengthening the protection of natural forest reserves and water conservation zones in the areas high in RDGS is an effective way to protect and improve the ecosystem service values in the Three Gorges Reservoir Region.