The Boussinesq and Flamant solutions for superimposed stress, combined with the Rankine earth stress theory, can be applied to calculate the active and passive superimposed stresses of retaining wall with vertical rectangular and strip load. The method can more accurately deal with the type and location and area of load and the influence of limit equilibrium state than the other methods can do, and can reveal the propagating change of external load by the fill, the calculating result is smaller. The calculations of some examples show that if the load location is of a distance away from the wall, the stress is zero at top of wall, but it will increase along the depth, and upto a value then decrease. If the load is located at the top of wall, the maximum stress is at the top and it will decrease along the depth. The stress in the case is greater than that at the first situation. Under the same condition, stress caused by strip load is greater than that caused by rectangular load.