Abstract: It was assumed that the trajectory of the minor principal stress behind a retaining wall took the form of a circle.Considering the effect of wall friction angle on the inclination of slip plane behind the wall,it was shown that the shapes of the minor principal stress arch and the average vertical earth pressures were different from those of the existing methods.The coefficient of earth pressure versus the angle of internal friction and the angle of wall friction was obtained.Using the coefficient in the method of horizontal differential element to compute active earth pressures on retaining wall,the theoretical formulae of the unit earth pressures,the resultant force and the points of application of the resultant force were derived.The proposed method was compared with the existing methods and some experimental data.