Abstract: Located in north-western China, Boston Lake is the largest fresh water lake in China. The eco-environment and water problems in the Boston Lake are very seriously. Based on the field investigations and the monitoring data during 1999-2001, the causes for ecosystem degradation and water problems in Boston Lake have been discussed by analyzing the changes of the lake water area and water quality, the withers of lake front and wet, and the damages of biodiversity. The results show that：the mainly pollution source for the degeneration of water environment in Boston Lake is by farmland draining water; the third quarter within a year is the highest season for polluting the water environmental in Boston Lake; The water body pollutant content is mainly consisted by the chloride ion, the sulfate radical, the mineralization, COD and the ammonia nitrogen and so on. The countermeasures for water environment protection and sustainable utilization of Boston Lake were proposed in the paper. Firstly, the pollution control in the basin should be down by establishing nature protection area of Boston Lake, enlarging the management and the law enforcement, strengthening management of dumps pollutants to the lake and strict control industry sewage to enter the lake. And secondly, some ecological engineering measures for water resources protection in the basin should be implemented through rehabilitating of lake front and wet, increasing the source and saving water in irrigation and speeding up water cycle of the Boston Lake.

Key words: Boston Lake, water environment, natural resources, ecosystem, water environmental protection, Xinjiang