Abstract: Based on the elastic-plastic theory, the critical edge pressure and critical loading of subsoil have been analyzed and stUdied with realistic coefficient of earth pressure at rest (K₀≠1)in this paper. Formulas of the critical edge pressure and critical loading were proposed and compared with the formulas in available reference. The critical edge pressure for subsoil obtained with proposed formulas is smaller than that in some reference. Some valuable conclusions are given.