[Objective] The water quality and eutrophication status were studied in order to provide a basis for its ecological restoration and rational development and utilization in Taiyangshan Wetland of Ningxia area.[Methods] The water samples were collected in April, July, October, 2019, and January 2020, the physical and chemical indicators of water environment factors were tested, and the phytoplankton density, biomass, the dominant species, Shannon-Wiener diversity index (H') and Pielou uniformity index (J) of phytoplankton were analyzed in Taiyangshan Wetland.[Results] The water quality in summer and autumn of West Lake was class Ⅲ, and that in spring and winter was class Ⅴ and class Ⅳ respectively. The water quality in summer and autumn of Nanhu Lake was class Ⅱ, and that in spring and winter was class Ⅳand class Ⅴ respectively. The water quality in Xiaonan Lake and East Lake was the worst and that was class Ⅴ in the whole year. The phytoplankton diversity index (H') was high, the variation of evenness (J) was small, and the water pollution was light in West Lake and Nanhu Lake. The change of phytoplankton diversity index (H') was obvious, and the water quality was poor in Xiaonan Lake and East Lake. The water body of West Lake presented slight eutrophication in summer and moderate nutrition in other seasons. The water body was moderately nutritious in the whole year in Nanhu Lake. The water body of Xiaonan Lake was moderately eutrophication in summer and autumn, and slightly eutrophication in spring and winter. The water body of East Lake presented a moderate eutrophication in summer and a slight eutrophication in other seasons.[Conclusion] The water quality of the Taiyangshan Wetland lakes has been polluted, and the degree of eutrophication changes significantly with the seasons. The water quality and eutrophication status of the lake should be closely monitored, and corresponding treatment measures should be taken in time.