In order to investigate the absorbing effects and/or impact resistant performance on arch-type RC entrance of tunnel with a sand cushion, falling-weight impact tests were conducted taking thickness of sand cushion and location of falling point for heavy-weight as variables. From these studies, the following results were obtained: 1) Punching shear failure occurred around arch crown may be restrained by applying sand cushion; and 2) Taking the standard thickness of sand cushion specified by Japanese guideline, impact resistant performance of arch-type RC structure can be improved more than 10 times referring to that of the structure without sand cushion.