Lake Wuli is a hyper-eutrophic, shallow-lake in China, situated near the Wuxi city in Jiangsu Province. It is a northern bay of Lake Taihu, which has a mean depth of 1.6 m, a maximum depth of 2.6 m and a surface area of 6.4 km². For improving water quality, from January 2004 a large-scale ecological restoration experiment (10x10⁴ m) has been carried out in southwestern Lake Wuli. Main measures applied include setting-up a large enclosure for facilitating growth of submerged macrophytes, sediment dredging, fish removal, rehabilitating sediment, stocking piscivorous fish, planting aquatic macrophytes, stocking benthic animals and so on. The results showed that 23 aquatic macrophyte associations had been set up, including 15 family, 22 genus and 32 species. The coverage of aquatic macrophytes increased from 0 to 40%-55%.Water quality has been markedly improved inside enclosure. The mean concentrations of TN, TP, NH4-N, NO3-N, NO2-N and PO4-P from August 2004 to July 2005 inside enclosure were 20.7%, 23.8%, 35.2%, 21.1%, 45.6% and 54.0% lower than those of outside enclosure. The mean concentrations of TN and TP were lower than 2.50 mg/L and 0.080 mg/L, respectively. Secchi depth was increased significantly from 0.39m to 0.70m. According to the results of this study, it is important and a first step to rehabilitate ecological structure and function in littoral of lakes, and to improve water quality gradually, and to establish submerged macrophytes at length. Biomanipulation could he applied to increasing secchi depth, reducing algal biomass and improving water quality in open area for whole lake restoration.