The problems that the horizontal static equilibrium of the slice with the sliding surface of soil arching effect is not possible in calculating the distribution of the unit earth pressure on retaining wall are presented. And according to the static equilibrium of horizontal-stratum soil in the sliding wedge

the equation of calculating the angle of failure line to horizontal are formed. Equations of calculating the unit earth pressure

the resultant earth pressure and the points of application of resultant earth pressure on retaining wall are set up. Comparison among the results calculated by formula presented here and the other methods and the experimental observations is made. It is demonstrated that the calculating results by this paper’s method have better safety and agreement with those of the experimental observations than those by the other methods.