Crashworthiness characteristics and axial collapse with damage propagation behavior of an aluminum/CFRP hybrid square hollow section beam were investigated under dynamic axial crushing load for crash box application. The low speed impact test referred to the RCAR regulations was performed with five different lay-up sequences and two different laminate thicknesses. Both tip ends of hybrid specimen were clamped by a specially designed jig to assign a similar boundary condition with an auto-body crash test model. Each different direction of carbon fibers offers respective crashworthiness characteristics, and the characteristics from each direction were mixed when stacked together. The specific energy absorbed and crush force efficiency were improved simultaneously up to 38% and 30%, respectively in the Al/CFRP hybrid SHS beam with a [0 degrees/90 degrees](2n) lay-up sequence, and they were slightly improved by increasing the thickness of the CFRP laminate.