PURPOSE: To prepare an automobile bumper having high impact strength and surface hardness, and excellent dimensional accuracy and heat resistance, by using a specific propylene block copolymer as a resin material.

CONSTITUTION: The objective bumper is repared by using, at least as a part of the bumper, a resin material having a melt flow rate of 0.1W30g/10min and composed of (A) 50W99pts.wt. of a random copolymer of propylene and a 5W12C α-olefin and (B) 50W1pts.wt. of a segment of an ethylene homopolymer or a random copolymer of ethylene and a 5W12C α-olefin and if necessary, propylene.