PURPOSE: To improve the wet preformance maintaining life by embedding a rubber body having the equal or nearly equal quality to a tread rubber into a tread rib, positioning the outer edge in the radial direction on the outside in the radial direction from the groove bottom of a tread main groove, and allowing a rubber body exposed through the wearing-out of the tread to be separated.

CONSTITUTION: A rubber body 18 which is made of the rubber material equal to or similar to a tread rubber and is previously vulcanized is embedded continuously in the circumferential direction of a tire, in two ribs 16 positioned on the center side of the tire width of a tread part 12. The rubber body 18 has a nearly rectangular form on the section in the tire radial direction, and the edge part 18a on the outside in the tire radial direction is positioned on the outside in the tire radial direction from the groove bottom 14a of a main groove 14. With this constitution, if the edge part 18a of the rubber body 18 is exposed through the wearing-out of the tread part 12, the rubber body 18 is separated from the tread part in simple manner, since the rubber body is previously vulcanized separately from the tread rubber, and a new groove is formed, and the wet performance is kept.