Based on the situation of food security and sustainable agricultural development,this research attempts to study systematically issues of potential grain productivity and potential yield increase in China by applying theoretical models (Agro-ecological Zone,AEZ) at 1km×1km grid and county levels with geographic information system(GIS) technologies.The results shows that in general the potential grain productivity tends to be higher in Southeast than in Northwest China,and the multi-years average potential photosynthesis productivity,phototemperature productivity,precipitation productivity and land productivity is 71.73t/hm2·a,19.71t/hm2·a,15.86t/hm2·a and 11.81t/hm2·a at 1km×1km grid level in China;the potential productivity at county level shows the same distribution model as that at grid level,and the average potential phototemperature productivity,precipitation productivity,water resources productivity and land resources productivity is 16.82t/hm2·a,13.74t/hm2·a,15.27t/hm2·a and 11.07t/hm2·a;the index of potential yield increase of phototemperature,water resources and land resources is 0.55,0.50 and 0.32,which shows that the present grain productivity has more than 1 double,1 double and 1/3 increase space according to the phototemperature potential productivity,water resources potential productivity and land resource potential productivity;and the development of grain production varies significantly among the counties studied,and the development of grain production in Inner Mongolia and Losses Plateau has a big space,while in Norhtwest China,Huang-Huai-Hai Plain and Sichuan Basin the increase of grain production has a small space.