To provide a one-piece solid golf ball which facilitates production, has an excellent recycling property and has flying performance equal to or better than that of the conventional golf balls.

This one-piece solid golf ball is produced by a thermoplastic elastomer compsn. which is formed by dispersing a diene rubber into thermoplastic resins and dynamically cross-linking this diene rubber by a cross-linking agent and has a modulus of elasticity in bending of 600 to 3500kgf/cm2. The thermoplastic resins are preferably ionomer resins, polyamide, polycarbonate, polyester, polyacetal, etc. The diene rubber is preferably ethylene-propylene-diene rubber, butadiene rubber, isoprene rubber, etc. The ratio of the thermoplastic resins and the diene rubber is preferably 30:70 to 95:5 by weight.