A metal-bonding adhesive composition consisting essentially of 95 - 60% by weight, based on the total composition, of an aliphatic homopolyamide and 5 - 40% by weight, based on the total composition, of an aliphatic copolyamide, said homopolyamide being a crystalline homopolyamide having up to 14 amide groups per 100 carbon atoms, and said copolyamide consisting of 90 - 70% by weight of (1) a polyamide having up to 14 amide groups per 100 carbon atoms and 10 - 30% by weight of (2) at least one polyamide whose recurring units are different from those of said polyamide (1), and a metallic can body composed of a metal blank, both side end portions of which are bonded by the side-lap-seam interposed by a layer of said adhesive composition.