In this study, in order to investigate impact resistant capacity of existing rockfall protection retaining wall, weight impact loading tests of the small-scale models were conducted taking foundation material, length of the wall, mass of the impacting weight as variables. The results obtained from this study were as follows: 1) angular velocity at the wall reaching the maximum rotation angle was a constant irrespective of kind of the foundation material and magnitude of length of the retaining wall; and 2) the coefficient of restitution e of the impacting weight tends to be zero due to increasing length of the retaining wall.