Abstract: The bearing capacity of roadbed is obtained based on the unified slip line theory and the unified strength theory(UST).The effect of strength difference in tension and compression and the intermediate principal stress effect are taken into account in the solution.The bearing capacities of roadbed were also analyzed using the finite element program ANSYS.The predicted values are compared with the solutions based on unified slip line theory and good agreement can be observed.It can be concluded that the unified slip line theory is suitable for analysis of the limit loads of roadbed.