The research introduced the current development of carrying capacity of environment and population size. Based on analysis of atmosphere environment bearing capacity and water environment carrying capacity, it further studied and summarized the soil environmental capacity on pollutants and social activities. The soil environmental capacity on pollutants is the maximum pollutants contained in a unit of soil within a limited time. Current research mainly focuses on background values, limit and migration coefficient of soil and the relevant modeling. The soil environmental capacity on social activities refers to the limit values of soil on the size,density and pace of development of social activities, while maintaining the normal structure and function of the bio-and eco-system of the soil. In other words, it not only refers to the capacity on pollutants, but also refers to the capacity on social and economic activities. Based on the research "Criteria on the standards of soil system", this report is mainly focused on the capacity of soil system on heavy metals. Further studies are still needed to come up with a universal definition of the soil environmental capacity and its theory system, as well as the standard and complete evaluating system.