Collision energy absorbing structure of vehicle

Disclosed is a collision energy absorbing structure of a vehicle capable of relieving impact by using a tubular pipe member (1) having equally-sized rectangular cross section and equal plate thickness and including no inside ribs and by adding a suitable trigger, and being easily manufactured at a low cost. By forming a cutout portion (1a) on the left side of the front end portion of the collision energy absorbing structure, the deformation starting portion (51) is provided. The cutout portion (1a) is formed at parts of three flat plate portions comprised of one of the four flat plate portions and corresponding opposite portions thereof. The general portion (52), which follows the deformation starting portion (51), is tubular with rectangular cross section and has a closed cross-section structure.