Abstract:[Objective] This study aims to determine the eutrophication status of Shahu Lake, Ningxia Hui Autonomous Region, and to calculate the environmental capacity of the lake for major pollution as a means of providing a basis for reducing the pollution load and improving the environmental protection of Shahu Lake.[Methods] Water samples were collected in January, April, July, and October during 2015-2017 to measure physical and chemical parameters. A comprehensive eutrophic state index was applied to assess the trophic status, and the Vollenweider and Dillon model was used to analyze the environmental capacity of permanganate index(CODMn), total nitrogen (TN), and total phosphorus (TP) of the lake under four different water quality target scenarios.[Results] During 2015-2017, Shahu Lake was mildly eutrophic in spring and winter, and moderately eutrophic in summer and autumn. In scenarios two and three of the water quality targets, the remaining environmental capacities for CODMn, TN and TP were zero. In scenario four, the remaining environmental capacity of the lake for TN was zero, whereas that for CODMn still had a remaining capacity. The environmental capacity of TN had a surplus in 2015, but this was reduced to zero in 2016-2017. On the basis of the water quality in 2017, to attain class Ⅲ water quality requirements, CODMn, TN, and TP should be reduced to 655.97, 39.27, and 1.41 tonnes, respectively, which correspond to reduction rates of 112.89%, 45.58%, and 37.60%, respectively. In order to attain class Ⅳ water quality requirements, the CODMn, TN and TP should be reduced by 0.0, 15.83, and 0.94 tonnes, respectively, which correspond to reduction rates of 0%, 18.37%, and 25.07%, respectively.[Conclusion] Shahu Lake has certain degree of pollution and has reached a state of eutrophication, the environmental capacities of CODMn, TN, and TP in the lake are greater than the target requirement, and should be managed and protected.