[Objective] The paper aims to estimate nitrogen pollution load in farmland in order to analyze environment pollution caused by livestock and poultry in China.[Methods] This paper estimated the amount of nitrogen nutrient of livestock and poultry based on statistical data. Then, the estimation and gridding of nitrogen pollution load of farmland were done using the method of area weighted interpolation and spatial analysis of GIS.[Results] The gridding of nitrogen pollution load of farmland was consistent with the basic characteristics of provincial data and the administrative boundary was no longer used as a basis for the division of nitrogen pollution load. The paper then used He'nan Province as s case study to verify the precision of gridding of nitrogen pollution load of farmland in China.[Conclusion] The dividing line of high value and low value of nitrogen pollution load of farmland coincided with the 400 mm isohyet. Among provinces in China, the higher nitrogen pollution load of farmland mainly occurred in Beijing City, Guangdong, Sichuan and Hu'nan Province. The lower nitrogen pollution load of farmland mainly occurred in Inner Mongolia Autonomous Region, Xinjiang Uygur Autonomous Region, Tibet Autonomous Region and Qinghai Province.