Utilizing export coefficient model and adopting RS and GIS techniques the authors estimated the non point source pollution load of Changyang County and simulated its spatial distribution. The results indicated as follows: The total nitrogen load caused by land use has increased 55.56%, and the total phosphorus load has increased 42.51% from year 2000 to 2006. The non point pollution has aggravated year by year. As far as spatial distribution, the non point pollution expanded from east of Changyang County to the west. The trend of deterioration was caused by the high strength land use exploitation and city-town outspread. Different land uses had various contributions to the total non point source pollution load. The gradation of contribution ratio to TN was from farmland to forest and grassland, and that to TP was from forest and farmland to grassland and land use for urban construction. The contribution ratio to the total non point source pollution load also has changed from 2000 to 2006. In terms of TN, farmland’s contribution ratio increased by 19%, and that of grassland decreased by 11%. However for TP, grassland’s contribution ratio drop 18%, and that of urban and residential area raised 5%.