Farmland circulation is the foundation of development of regional farmland market. With the aid of survey data of Jiangsu Province and using Heckman two-stage method, this paper analyzed factors influencing farmland circulation from supply and demand of land. Results showed that non-agricultural employment, social security level, and regional economic development level are key factors. In view of these factors, it is recommended to improve rural labor quality, establish perfect rural social security system, and constantly improve rural security level, which are fundamental ways to promoting farmland circulation and improve circulation market.