Abstract: Using the Universal Soil Loss Equation (USLE) and GIS technique,this study ① modeled the spatial distribution of soil retention ecosystem service in the Three Parallel Rivers Region,② analyzed the distribution of the service on different elevation zones,and land-use types,and ③ assessed the capacities of different ecosystem types in providing the service.The results showed that ① the annual total of soil retention in the Three Parallel Rivers Region was 5.10×109 t·a-1,averaged 767.66 t·hm-2·a-1;② the high-value regions of soil retention service were primarily located in the riverside areas of Nu River in south-central Lushui,Lancang River in central Yunlong,Jinsha River in northeast Yulong,and the east areas in Binchuan,mainly in the forest land ranged from 2 000 to 3 500 meters in elevation;③ semi-humid broad-leaf evergreen forest had the highest soil retention capability,followed by mid-montane humid broad-leaf evergreen forest,warm conifer forest,monsoon evergreen broad-leaf forest,hot-dry valley sclerophyllous evergreen oak forest,and warm temperate shrub-grassland,while sub-alpine meadow had the lowest soil retention capability.We concluded that climate,topography,land-use patterns and vegetation cover as well as the interactions among them are the main factors that affect the spatial pattern of soil retention ecosystem service in this region.