To provide the novel solution to a problem of a flat parting line for a golf ball by redesigning a mold for forming the golf ball.

The mold for the golf ball having the non-flat parting line and a cover forming method utilizing such molds are disclosed. This mold includes a pair of the molds consisting of the halves of the respective molds. The halves of the respective molds have non-flat peripheries. The non-flat peripheries have alternately extension parts and recessed parts. The respective extension parts have curved apexes and the respective recessed parts have curved recesses. The mold forms layers to the golf ball by compression molding, injection molding and casting molding. The mold may be utilized for manufacture of the golf ball having a non-dimple surface.