PURPOSE: To absorb and relax impact force to a propeller shaft at the time of vehicle collision by letting the propeller shaft be composed of both a first and a second shaft section located at the front and rear side, which are connected to each other via an universal joint, and enabling the first shaft section to be extracted/contracted.

CONSTITUTION: When a differential gear at the front side is retreated at the time of vehicle collision, a first shaft member 1A is pushed on with pressure. In this place, since the first shaft member 1A is composed of an outer cylinder 31 and of an inner cylinder 32, which are fitted in through splines in such a way as to be freely slid, afterward impact energy can be absorbed by letting the locking force of a stopper ring 40 be crushed by the outer cylinder 31 at the front side, and thereby letting the outer cylinder be slid by a specified stroke roughly in the horizontal direction at the rear side. As a result, the deformation behavior of the propeller shaft is controlled so as to be stabilized afterward roughly in the horizontal direction, no irregular deformation such a case that the shaft is bent into a cabin, will never take place.