A pneumatic tire comprises a tread portion, the tread portion is provided in a center region with a row of long blocks and wide blocks which are disposed alternately in the circumferential direction of the tire, the center region has 30% of the tread width, the long blocks are such that the circumferential length (a) is larger than the axial length L1, the wide blocks are such that the axial length L2 is larger than the circumferential length (b), the ratio (a/b) of the circumferential length (a) and the circumferential length (b) is 1.1 to 1.5, and the ratio (S1/S2) of the surface area S1 of the long blocks and the surface area S2 of the wide blocks is 0.40 to 0.77. Preferably, the axial length L2 of the wide blocks is 18 to 30% of the tread width, and the long blocks and wide blocks are disposed such that at least one of the long blocks and at least one of the wide blocks appear in the ground contacting patch of the tire.