Abstract: In order to study the origin of the particilate nitrogen and phosphorus(PN(P)) nonpoint source (NPS) pollution there,so as to get it under control,some artificial rainfall experiments was made around Guanting Reserwir.the results show that the correlation between transporting rate of PN(P) and yielding rate of sediment is very good,with the average correlation coefficient 0.9594 and 0.9772 for PN and PP respectively.Therefore,a new load model of PN(P) is put forward,in which enrichment coefficient is equal to the ratio of the percent content of total nitrogen (total phosphorus) in sediment to it in mil.While applying it,we study the spatial distribution of PN(P) loadon the Guishui watershed according to the DF1VI and the information obtained from land use map and mil map.Its results show that PN(P) mainly originated from hill and mountains where the ratio of vegetative cover is very low.