A groove bottom of a circumferential groove formed in a tread surface is provided with a protruding stripe extending along a next ending direction of the circumferential groove. The protruding stripe is provided with a top head portion protruding toward a tire outer circumferential side, and a base portion which is narrower than the top head portion and connects the top head portion and the groove bottom. If a small stone is pinched, the top head portion is inclined around the base portion, and the protruding stripe is deflected as a whole, thereby generating a reaction force on the basis of a deformation restoring force.