A hydrogenated diene copolymer resin composition comprising (A) 5-70% by weight of a hydrogenated diene copolymer which is a hydrogenation product of a random copolymer of at least one conjugated diene and 3-50% by weight of an alkenyl aromatic compound having a number average molecular weight of 5,000-1,000,000 and a molecular weight distribution (Mw/Mn) of 10 or less, the vinyl content in the diene portion of the random copolymer being 10-90%, at least 70% of the olefinic unsaturation of the random copolymer being hydrogenated, and (B) 95-30% by weight of at least one resin selected from the group consisting of a polypropylene resin, a polyphenylene ether resin and an alkenyl aromatic compound polymer resin. The hydrogenated diene copolymer (A) can be used in combination with (B) a polyphenylene ether resin and (C) at least one member selected from the group consisting of a polyamide and a thermoplastic polyester in such a proportion that the amount of (A) is 1-50 parts by weight, the amount of (B) is 10-89 parts by weight and the amount of (C) is 10-89 parts by weight. The above composition has improved impact resistance and improved gloss and appearance of molded article.