Abstract: Occupation-Addition balance of the cultivated land, and especially that of basic farmland, has direct relationship with food security. So it has a great significance to keep the balance in quantity and quality. First, the paper discusses the occupied basic farmland’s location and the calculation of its comprehensive quality based on the classification result of agricultural land and GIS spatial analysis technology. Second, it analyzes the principles of changing the ordinary farmland into the basic farmland, including the quality and level of the ordinary farmland, the distance between the ordinary farmland and traffic trunk lines and town and rural residential locations, as well as the concentration of the basic farmland after the change. At last, according to the analysis above, the paper determines the location and quantity of the ordinary farmland that can be added into the basic farmland with GIS technology.