Abstract The side members of automobile, such as the hat shaped section members, absorb the most of the energy during the front-end collision. The purpose of this study was to analyze the collapse characteristics of hat shaped section members. The hat shaped section members consist of the spot welded member, which was utilized to an actual vehicle and CFRP member for lightweight of vehicle structural member. The spot welded hat shaped section member was made of SCP1 cold rolled steel sheet and the CFRP (carbon fiber reinforced plastics) hat shaped section member was made of CFRP prepreg sheet. The hat shaped section members were tested under static axial loading by universal testing machine. The CFRP members exhibit collapse modes that are significantly different from the collapse modes of the spot welded member. The collapse mode and the energy absorption capability of the each section members were analyzed and compare the results of spot welded member with those of CFRP member.