Cultivated land is the most efficient soil among the land for agriculture.Reasonable exploitation of cultivated land concerns developing speed of the national economy,safety of grain production,higher yields of better quality crops,and preservation of quality and quantity of the land resources.Through analysis of current and potential productivity and future living standard,a basic thought for rational disposition of cultivated land resources is presented in this paper.Namely,keeping 3,670.67km² of cultivated lands could guarantee the safety of grain production and the ratio of 6:4 is a suitable proportion of grain and cash crops for the agricultural structure.Besides,this article also provides suggestions for sustainable uitilization of cultivated land resources.