Lake Taihu basin is an economic developed area with almost the highest population density and the most concentrated cities and towns in China. But it is also one of the most seriously degraded great lake basins due to ecological destruction and eutrophication development. At present, water pollution of Lake Taihu has exerted enormous influences on sustainable development of the basin, and produced greater threat to the health of people surrounding the lake. Therefore, it has been an urgent task for local governments and technical staff to take measures for the protection and treatment of Lake Taihu. Based on the analysis of present state and development trend of water quality and pollution sources of Lake Taihu, key pollution control regions and corresponding engineering plan for comprehensive treatment of the lake were put forward.