Crash box is a thin-walled structure. It installed between the bumper and the frame on the front of the vehicle is a very important part as the impact energy absorber in this frontal collision front crash. To improve crashworthiness characteristics .has done some research. They are material selection, design parameter, joining technicques for enhanced specific energy absorbed and crush force efficiency. Few study for composite material and natural fiber used as crash box. In this study, natural fiber of Musa acuminata balbisiana used as reinforcing composite material for hybrid aluminum square crash box