PURPOSE: To provide a compsn. which has excellent heat resistance, shock resistance and tensile strength and which is useful for a formed article by mixing specified proportions of each specified polyolefin, aromatic vinyl polymer and org. compd.

CONSTITUTION: This compsn. contains (A) 10 to 90 pts.wt. of one or more kinds of modified polyolefins prepared by grafting unsatd. carboxylic acids (derivs.) such as acrylic acid or a mixture of these to polyolefins, (B) 10 to 90 pts.wt. of a modified aromatic vinyl polymer or copolymer of vinyl aromatic monomers prepared by grafting unsatd. carboxylic acids (derivs.) or a mixture of these to aromatic vinyl polymers or copolymers of aromatic vinyl monomers and (meth)acrylonitrile, and (C) 0.1 to 7 pts.wt. of an org. compd. such as hexamethylene diamine containing two or more primary or secondary amino groups.