A tire comprising a block row formed in a center region including a tire equatorial line having blocks (100, 110A, 110B, 110C), each of which has a tread contacted with a road surface, arranged adjacent to each other in a tire width direction and a tire circumferential direction in a tread surface view, wherein: each of the blocks (100, 110A, 110B, 110C) includes a radial direction outer portion formed at a side of the tread, and a radial direction inner portion formed at an inner side in a tire radial direction of the radial direction outer portion; characterized in that: an entire circumferential edge of the blocks except the blocks arranged in width direction edge of the block row is defined against an adjacent block adjacent to the block by a sipe in the radial direction outer portion; an inner side groove is formed at an inner side in the tire radial direction of the sipe; at least a part of the inner side groove is communicated with the sipe; and the entire circumferential edge is defined against the adjacent block by the inner side groove in the radial direction inner portion, wherein: a part of the circumferential edge is defined by a leading groove instead of the sipe in a certain block among the blocks (100, 110A, 110B, 110C); a leading groove portion is formed by the leading grooves communicated with each other; and the leading groove portion is formed in a projection shape projected toward one side of a tire circumferential direction. each of the blocks (100, 110A, 110B, 110C) includes a radial direction outer portion formed at a side of the tread, and a radial direction inner portion formed at an inner side in a tire radial direction of the radial direction outer portion; characterized in that: an entire circumferential edge of the blocks except the blocks arranged in width direction edge of the block row is defined against an adjacent block adjacent to the block by a sipe in the radial direction outer portion; an inner side groove is formed at an inner side in the tire radial direction of the sipe; at least a part of the inner side groove is communicated with the sipe; and the entire circumferential edge is defined against the adjacent block by the inner side groove in the radial direction inner portion, wherein: a part of the circumferential edge is defined by a leading groove instead of the sipe in a certain block among the blocks (100, 110A, 110B, 110C); a leading groove portion is formed by the leading grooves communicated with each other; and the leading groove portion is formed in a projection shape projected toward one side of a tire circumferential direction. an entire circumferential edge of the blocks except the blocks arranged in width direction edge of the block row is defined against an adjacent block adjacent to the block by a sipe in the radial direction outer portion; an inner side groove is formed at an inner side in the tire radial direction of the sipe; at least a part of the inner side groove is communicated with the sipe; and the entire circumferential edge is defined against the adjacent block by the inner side groove in the radial direction inner portion, wherein: a part of the circumferential edge is defined by a leading groove instead of the sipe in a certain block among the blocks (100, 110A, 110B, 110C); a leading groove portion is formed by the leading grooves communicated with each other; and the leading groove portion is formed in a projection shape projected toward one side of a tire circumferential direction. a part of the circumferential edge is defined by a leading groove instead of the sipe in a certain block among the blocks (100, 110A, 110B, 110C); a leading groove portion is formed by the leading grooves communicated with each other; and the leading groove portion is formed in a projection shape projected toward one side of a tire circumferential direction.