The 2011 off the Pacific coast of Tohoku Earthquake triggered devastating tsunami which caused various structural damages to RC buildings. Impact tests were conducted using a lateral impact loading system to evaluate the performance of RC wall specimens. The damage of twenty RC wall specimens was classified into penetration, scabbing, and perforation. In order to evaluate the limit impact velocity for scabbing and perforation, the modified Hughes formula was proposed by assuming that tensile concrete strength is a constant value (1.76 N/mm2) regardless of the splitting tensile strength of accompanying cylindrical specimens. The proposed formula perfectly classified the local damage of twenty specimens in this study.