With the aid of GIS(Geographical Information System),remote sensing technology,and the SWAT(Soil and Water Assessment Tool) model developed by the ARS(Agricultural Research Service) of the USDA(United States Department of Agriculture),relevant parameters essent ial to the SWAT model were extracted from Lianshui Basin,Xingguo County,Jiangxi Province,and computer simulation of chemical composition of the runoff in the study area was carried out,Twelve typical subbasins varying sharply in simulation value from 1993 to 2000 were selected for analysis of relationship between land use and simulated chemical composition,using the land use maps of the two time periods.Results show that land use was closely related to translocation rates of organic N,organic P,nitrate N,Soluble P and Mineral P.The findings of the study can be used as technical aid and basis for sustainable development of the agriculture,comprehensive administration and programming of the basin,and realization of agricultural BMPs(Best Management Practices).