Abstract: Wanshan Lake in Taihu Watershed was selected as the research area to explore the effect of ecological restoration on the improvement of water quality and the impact on the metabolic function of microbial community. Aiming to the restoration of aquatic plants, measures such as reshaping of topography and establishing of ecological buffer zone were taken to create suitable ecological environment conditions in Wanshan Lake from March to June of 2019. The aquatic plants and water quality in the northwest part of the lake including restoration area, pelagic area and control area were monitored from August 2019 to August 2020. Biolog technology was used to analyze the metabolic functions of microbial community in the research area in summer after the recovery of aquatic plants. The results show that the species, coverage and diversity of aquatic plants, especially for the submerged aquatic plants, in the restoration area were largely improved. The transparency of water body was significantly improved in the restoration area, which was 23% and 30% higher than that of the pelagic area and the control area, respectively. The concentrations of TN, NH₄⁺-N and TP of the restoration area were 32%, 28% and 28% lower than that of the pelagic area, respectively, and 19%, 32% and 31% lower than that of the control area, respectively. Moreover, the removal of Chl-a and COD_Mn were insignificant, which was related to the geographical location and hydrology of the restoration area. The recovery of aquatic plants could promote the response of microbial communities to utilize organic matter and then improve the metabolic activity of microorganisms and self-purification ability of the lake.