Abstract: In Ming-Qing historic circles in China and Japan, the studies of troops and police as an organ of violence have been very few up to mow. Based on the lowest stratum organization “xun” of the Qing Green Standards, this paper examines its policing functions and the relation between it and regional society in the Jiangnan delta. The paper affirms that the Xun’s jurisdiction was limited to the region of town on the whole. In other words, the main policing function of Green Standards in the Jiangnan delta was protecting communications in market towns.