Provided by the present invention is a technique which can, in a pneumatic radial tire using corrugated steel cords in the circumferential bent, improve the durability of the corrugated steel cords in order to prevent fatigue rupture thereof caused by an increase in energy input.The present invention is a pneumatic radial tire which has a carcass 1 as the skeleton extending in a toroidal shape between a pair of bead portions on either side of the tire, as well as a belt layer 2 and a tread layer 5 successively arranged thereonto at the outer part in the tire radial direction. The belt layer 2 comprises at least one layer of circumferential belt 3 which comprises a plurality of corrugated or zigzag-shaped steel cords extending along the tire circumferential direction, and when the steel cords are removed from the circumferential belt 3, the bending radius of curvature (R) of the steel cords is within the range from not less than 18 mm to not more than 125 mm.