To prevent generation of mold biting, mold rubbing, and the like even when vulcanization is carried out in a full mold by specifying a cord density of a belt central reinforcing layer within the predetermined value for a cord density of belt both side reinforcing layers and adding expansion within the predetermined value during vulcanization of the belt both side reinforcing layers and the belt central reinforcing layer.

A belt is stuck on a BT drum, and on its both sides, a pair of left and right belt both side reinforcing layers are formed on the outside in the radial direction. A rubber coating cord layer, in which a single cord or a plurality of cords arranged in parallel is or are buried, is wound spirally while shifted sequently in the tire axial line direction. In this process, on the tire axial line directional inside of the belt both side reinforcing layers, a belt central reinforcing layer, whose cord density is 10-30% of that of the belt both side reinforcing layers, is formed. In vulcanization of the belt both side reinforcing layers and the belt central reinforcing layer, expansion of 0.5-5% is applied to them.