Abstract: In order to understand the relationship between land use change and water quality in theXingyun Lake basin, the paper interpreted land use information from high-resolution remote sensing images in the past 30 years, which was divided into seven land use types: farmland, forest land, grassland.construction land, transportation land, water and bare land, then analyzed the correlation between landuse types and water quality. The results indicate that 1) the main land use types in the study area are fiveypes: farmland, forest land, grassland, water and construction land, and arious land types have changed significantly during the development of Xingyun Lake basin.Construction land and transportationland increased significantly , which mainly occupying farmland and grassland. Grassland and bare land isgradually decreasing, and a large amount of grassland is converted into farmland and construction. Waterfluctuates within a small range, and forest land has become fragmented. Farmland has increased, whosemain source of inflow is grassland and forest land, and the main flow is construction land and transportation land. 2) The water pollution indicators of Xingyun Lake did not change significantly before 1995and the water quality was classified as Class ll. Since 2000, the water pollution index has gradually in.creased, and water quality had dropped to ClassIV. After 2005 , the water deteriorated significantly, andwater quality dropped to Class V , which was in a moderate-severe eutrophic state. 3) There was a strongpositive correlation between water pollution indicator and farmland, construction land, transportation landin Xingyun Lake basin, which indicated that the deterioration of water quality may be the result of thecombined effects of agricultural non-point source pollution, domestic and industrial pollution sourcesThere was a signifcant negative correlation between water pollution indicator and grassland, bare landwhich indicated that the permeable underlying mat had significant interception and absorption effects onpollutants.

Key words: Xingyun Lake, land use, water quality, correlation