Nansihu lake, one of the major freshwater lakes in China, is regarded as important water resources in Shandong Province.With construction of the energy base and the development of social economy, many environmental problems in the utilization of water resources and the exploitation of coal resources have been raised in the area.This paper discusses the condition and causes of formation and development of these problems such as falling of ground water stage, water pollution, lake swamping, surface subsidence, soil and water erosion, soil salinization.In the end, some countermeasures of protecting the water environment of this area are put forward.