Nutrient export coefficient of land use is an important parameter for constructing model of non-point source pollution. Xitiaoxi watershed located in Taihu lake region

11 representative sub-watersheds were delineated and selected by GIS. Land use data derived from Spot satellite images in 2004. TN/TP concentrations were measured by 3 times in Jul.

Sep. and Dec. of 2004 at outlets of these sub-watersheds. The relationship between land use composition and nutrient export was qualitatively analyzed

the result showed that nutrient export increase with a higher percentage of arable land area and a lower percentage of forest land area. Based on this result

the quantitative equation between percentage of land use area and TN/TP concentration was established. TN/TP export coefficient for arable land is 4. 747 3 mg/L and 0. 089 6 mg/L

and TN/TP export coefficient for forest land is 0. 271 3 mg/L and 0. 007 5 mg/L.