A pneumatic tire comprising: a tread reinforcing layer disposed radially outside a carcass in a tread portion, the tread reinforcing layer including a mesh reinforcing layer formed from a tape of rubber in which a reinforcing cord or parallel reinforcing cords are embedded along its length, wherein in the mesh reinforcing layer, the tape is wound circumferentially of the tire plural turns while repeating a zigzag unit in the tire circumferential direction, the zigzag unit comprises a first inclined portion, a second inclined portion, and a turning portion connecting therebetween, in the first inclined portion, the tape extends from a first side edge on one side in the tire axial direction of the mesh reinforcing layer to a second side edge on the other side in the tire axial direction of the mesh reinforcing layer while inclining to one side in the tire circumferential direction, in the second inclined portion, the tape extends from the second side edge to the first side edge of the mesh reinforcing layer while inclining to one side in the tire circumferential direction, the mesh reinforcing layer comprises a number N of the repeated zigzag units arranged while shifting in the tire circumferential direction and partly overlapping with each other, the amount of positional shift in the tire circumferential direction between the circumferentially adjacent zigzag units is in a range from 0.7 to 1.3 times a value of 360/N in terms of the angle α around the tire rotational axis, and the mesh reinforcing layer has parallelogram-shaped meshes formed by the first inclined portions and the second inclined portions of the zigzag units which intersect with each other, characterized in that the circumferential lengths of the meshes are gradually decreased from the axially inside to the axially outside of the tire. a tread reinforcing layer disposed radially outside a carcass in a tread portion, the tread reinforcing layer including a mesh reinforcing layer formed from a tape of rubber in which a reinforcing cord or parallel reinforcing cords are embedded along its length, wherein in the mesh reinforcing layer, the tape is wound circumferentially of the tire plural turns while repeating a zigzag unit in the tire circumferential direction, the zigzag unit comprises a first inclined portion, a second inclined portion, and a turning portion connecting therebetween, in the first inclined portion, the tape extends from a first side edge on one side in the tire axial direction of the mesh reinforcing layer to a second side edge on the other side in the tire axial direction of the mesh reinforcing layer while inclining to one side in the tire circumferential direction, in the second inclined portion, the tape extends from the second side edge to the first side edge of the mesh reinforcing layer while inclining to one side in the tire circumferential direction, the mesh reinforcing layer comprises a number N of the repeated zigzag units arranged while shifting in the tire circumferential direction and partly overlapping with each other, the amount of positional shift in the tire circumferential direction between the circumferentially adjacent zigzag units is in a range from 0.7 to 1.3 times a value of 360/N in terms of the angle α around the tire rotational axis, and the mesh reinforcing layer has parallelogram-shaped meshes formed by the first inclined portions and the second inclined portions of the zigzag units which intersect with each other, characterized in that the circumferential lengths of the meshes are gradually decreased from the axially inside to the axially outside of the tire.