To provide a soft golf ball with a good shot feeling which is free from peeling of coated layers, with excellent durability and with an improved shot feeling without decreasing a repulsive force.

The one piece golf ball comprising a ball body made of a vulcanized rubber composition and a coated layer on the surface of the ball body. 0.1-5.0 mass part of silane coupling agent is contained in 100 mass of the rubber base in the rubber composition. The rubber composition preferably contains 10-100 parts of an alpha, beta-unsaturated carboxylic acid and/or its metal salt as a co-crosslinking initiator, and 0.1-5 mass part of an organic peroxide as a crosslinking initiator, as swell as further containing 5-50 mass part of a filler with a specific gravity more than 2.5.