According to the results of an eight-year study, the effects of soil region, the distribution of zonal soil type and pH, carbonate and organic matter on regional differentiation of critial concentrations and environmental capacities of Cd,Pb,Cu and As in soils are analysed, and the pH value of soil and the distribution of soil type are concidered as the main influenting factors. there was a negative correlation between the critical levels and environmental capacities of Cd and Cu in soils and the pH of soils. The critical levels and environmental capacities of Cd and Cu in soils decreased with the distribution of soil types from south to north. The critical levels and environmental capacities of As in soils increased with the soil pH and the distribution of soil types from south to north, but there was no correlation between them.