Abstract: Based on GIS technology,the agricultural non-point source pollution potential index(APPI)system was applied to analysis of spatial distribution of agricultural non-point source pollution potentials and pollution loads of the Shayin River Catchment,a typical semi-arid area,consisting of 46 administration villages in Huangqiao Township and Xixiating Town of Xihua County,Henan Provice.The APPI system was also applied to the identification of priority control areas and priority control factors,caculation of N and P loading intensities per unit area and total loads of every village,and determination of types of the sources of these pollution loads.Results show that as a whole,in the study area nitrogen is the major factor of the pollution,which mainly comes into the environment with nutrient loss from farmlands and the from reaing of livestrock and poultry,contributing 52% and 40%,respectively,to the total pollution load.Dayangzhuang,Zhangzhuang and Qianji are identified as high risk areas and priority control areas,ranking in the top of the list of villages in terms of APPI index,N and P pollution load per unit area and total pollution load,of which the main cause is rearomg of livestock and poultry.

Key words: agricultural non-point souce pollution, agricultural non-point source pollution potential index(APPI), Shaying River Catchment, geographical information system