[Objective] With the continuous increase in grain output and agricultural policies adjustment during 1990-2012

the temporal-spatial evolution of grain production and its driving mechanism was studied in order to provide theoretical support for food security policy making in Huaihe River basin.[Methods] The space center and spatial pattern of grain production were analyzed dynamically based on the regional gravity model and spatial autocorrelation method.[Results] (1) The total grain output and per county grain output increased since 1990s. The counties with high grain production distributed in the middle part of Huaihe river basin

while the counties with average grain production distributed toward the middle and up part of the basin. (2) The space center of grain production in Huaihe river basin moved to west and south and the center of grain production moved to the Shuixi County of Anhui Province from the Central Jiangsu Province during the study period

and the spatial pattern tend to be stable. (3) The counties with high grain production tend to aggregate in the junction area between He'nan and Anhui Province and the counties in coastal area of Central Jiangsu Province. While the counties with low grain production tended to cluster in the edge area of western He'nan Province. The number of counties with the aggregation of high-low and low-high is small

but its spatial distribution changed greatly.[Conclusion] The dominant factors

such as water and soil resources change

new agricultural technology and policy inclination

grain comparative benefits

common drive the evolution of basin spatial pattern of food production.