Abstract: Based on the evaluation and analysis of last round of land use overall planning of Guang'an (1997~2010)，this paper finds in the last round land use overall planning there are such deficiency as excessive quantity (256836.36 hm2)of the protected prime farmland, too much emphasis in the index control but relatively too little in the space control, the Lack of scientific planning for the position of the protected prime farmland, etc. Through the study of prime farmland protection status, the number (223897.53 hm2) of protected prime farmland and key prime farmland to be protected in the new round land use overall planning of Guang'an is determined. Under the new situation, in the new round of the land use overall planning, prime farmland protection will be carried on in the aspects of index, space, quality and type to ensure food security in Guang’ an