Abstract: A thermoplastic elastomer composition which comprises (I) 99 to 1% by weight of a hydrogenated diene copolymer having a number average molecular weight of 50000 to 700,000 in which 80% or more of the double bonds of the conjugated diene portion of the conjugated diene polymer have been saturated, (II) 1 to 99% by weight of an ionomer resin having an .alpha.-olefin unit having 2 to 8 carbon atoms and an .alpha.,.beta.-unsaturated carboxylic acid unit, at least part of the carboxyl group of said unsaturated carboxylic acid unit having been neutralized with a metal ion, and (III) 0 to 70% by weight of a polyolefin resin, provided that (I)+(II)+(III)=100% by weight. Said composition is excellent in moldability and gives a molded article excellent in transparency, flexibility, mechanical strength, heat resistance and impact resilience.