Abstract: Carbon storage and sequestration potential of a cropland soil are key factors in assessing emission reduction of greenhouse gas.In this paper,the carbon sequestration potential of croplands in China was analysed based on the topsoil's organic carbon content.Studies showed that the overall organic carbon content of the cropland topsoil in China was on the rise.In both paddy field and dry land soils,the organic carbon content increased significantly over the years.And,the capacity to sequester carbon dioxide of the paddy fields was much stronger than that of the dry land.The soil's carbon sequestration potentials differed depending upon the environment.On a macro-scale,the sequestration science,dynamics,environment and aggregative model have been applied to study the soil's carbon sequestration potential,so as to understand the various roles of the factors in search for means to better manage the soil carbon.