To solve such a problem that an earth retaining wall falls, slides or concrete breaks when an impulsive force of collapsed earth and sand colliding with the front face of the retaining wall because the retaining wall is designed without consideration of an impulsive force of falling earth with consideration of only the static earth pressure after the front face of the retaining wall is filled with collapsed earth, in the design, and hence, when the force exceeds the designed bearing force, earth overrides the retaining wall and damages the rear face building of the retaining wall.

The protection structure of the retaining wall reduces the collapse impulsive load of collapsing earth by mounting a buffer on the front face of the retaining wall, further, by interposing the buffer between an impulsive force receiving board and a base board as an integral body.