A pneumatic tire is provided with a pair of circumferential grooves (3) arranged in both sides of a tire equator (C), and a plurality of oblique grooves (4) having a steep decline portion (4a) extending to an outer side in a tire axial direction at an angle (q1) between 15 and 45 degree with respect to a tire circumferential direction from a position near the circumferential groove (3), in a tread surface (2). A land portion (B) surrounded by the circumferential groove (3) and the steep decline portion (4a) has an acute corner portion (12) and an obtuse corner portion (13), each being formed between the circumferential groove (3) and the steep decline portion (4a). An outer groove wall surface (6) of the circumferential groove (3) includes a gentle decline wall (6a) in the tread surface side, and a steep decline wall (6b) in the groove bottom side.