PURPOSE: To provide a thermoplastic elastomer compsn. consisting of styrenic block copolymer rubber and non-crystalline vinyl acetate/ethylene copolymer rubber and having excellent kneadability, moldability and high-frequency weldability.

CONSTITUTION: Styrenic block copolymer rubber (A) having a styrene content of about 10W50wt% and containing a polystyrene segment as a hard segment and a polybutadiene segment as a soft segment in one molecule (e.g., "Solprene T- 411 , a product of Asahi Kasei Co.) and non-crystalline vinyl acetate/ethylene copolymer rubber (B) with a vinyl acetate/ethylene ratio of about 45:55W85:15 by weight and a Mooney viscosity (M1+4 at 100°C) of about 10W70 are mixed at about 100W150°C by means of a roller, pressure kneader, etc. For better kneadability, (A) and (B) are used in a blend ratio of around 80:20W20:80 by weight.