When cultivated land is designated as basic farmland,the goals of land protection plan are mainly considered,while regional differences in resource endowments are usually neglected.With the help of spatial analysis technologies and previous studies on land suitability evaluation,this paper points out that the designation of basic farmland should be based on land suitability index and present situation of land use.By taking Siyang County as an example,basic farmland designated using the new method is 577.5 km2,about 84.8% of total cultivated land.The proportion of basic farmland in the north and the south of Siyang County is relatively high because its land suitability index is high.The proportion of basic farmland near Siyang County and main roads is relatively low because of high construction land demands.The result indicates that we should take regional differences in resource endowments into consideration while converting cultivated land into basic farmland,so as to coordinate the contradiction between land protection and economic growth.