Grey correlation coefficient analysis was employed to explore the relationship between landscape pattern idices of constraction land in Dianchi Lake basin and water TN,TP concentrations in Dianchi Lake. The results showed that the concentration of TN and TP in Caohai and Waihai of Dianchi Lake had been increasing obviously during 1988-2008;In Dianchi Lake basin,the agglomeration and integration level and size of construction land patches increased constantly while the distance between the land use patches decreased, the shape of the land use patch tends to be more complex and irregularly;the impacts of construction land use on water quality were closely related with the spatial land use pattern,especially the degree of polymerization and the mean area-weighted of fractal dimension.To guarantee the water safety for the rapid development of urbanization in Dianchi Lake basin,the basic land-use adjustments to retain sufficient ecological land in the lakeside area,to avoid the excessively integration of construction land and the formation of big size of construction land patches was proposed.