Abstract: To study the water environment and eutrophication of Dongping Lake and take effective measures to protect the lake, the history change of water environment, the present situation of water quality and eutrophication and pollutant sources of Dongping Lake were reviewed though field survey and literatures. The results showed that the changes of water environment of Dongping Lake were mainly influenced by the Yellow River before 1960s, and since then the change of the water environment of Dongping Lake was mainly influenced by human activity. Under the combined action of endogenous pollution such as sediment resuspension and degradation of dead Potamogeton crispus and exogenous pollution such as industrial anddomestic sewage, eutrophication of Dongping Lake had been developed into middle-to-rich level. Finally, the authors made an outlook for the future development of water environment of Dongping Lake based on the present situation of water environment governance and the plan of eastern route of south- to- north water transfer project.