Abstract: Chishui River, as an important tributary in the south bank of the upper Yangtze River, is an important part of the development strategy of the Yangtze River Economic Belt in China.SWAT model was used to simulate the river runoff characteristics of the Chishui River Basin in Yunnan Province.Combined with the pollution source investigation and accounting, the water environment carrying capacity was measured to provide basic supports for the formulation of ecological compensation scheme and the implementation of spatial managements of ecological environment.The results showed that:(1) The annual average runoff of the mainstream of Chishui River and the important tributaries, Zhaxi River, Daoliu River, Tongche River and Shuanghe River were about 0.700,0.158,0.297,0.200 and 0.021 billion m3 respectively, which showed obvious spatial distribution difference.(2) In 2017,the total emissions of COD,NH3-N and TP into rivers were 5330.89,500.46 and 102.52 tons respectively in the study area.The main source of pollution was urban living source.(3) The total allowable discharge of COD,NH3-N and TP were 26328.99,1834.38 and 402.09 tons per year, respectively.The remaining water environmental capacities were 13833.98,696.59 and 129.46 tons per year.For Zhaxi River, the water environment carrying capacity has been overloaded.