Abstract: The surveys show that the water storage of Baiyangdian Lake is only 1/10 of that during 1960's, and the water quality of Baiyangdian Lake has been still becoming worse and worse, the water area with water qualities of grade Ⅳ is 29.7% of the total area, and the area of grade Ⅴ is 51.4%, and the area that is worse than grade Ⅴ is 18.9%. The pollutant sources in Baiyangdian Lake are mainly organic contaminants, in which COD_Mn (chemical oxygen demand), TN(total nitrogen) and TP (total phosphate) are much higher than the standards, and BOD₅ (biochemical oxygen demand) is more of less contaminated too. Totally, the water environment in Baiyangdian Lake is of light eutrophication. Finally, the strategies to control water pollution of the lake are put forward.