PURPOSE: To obtain a tire having good high-speed durability and wear resistance and well suited to heavy load and high-speed radial tire by dividing a tread into a tread-central part and tread side parts at a specified ratio, and constituting the respective parts by specified rubber-composites.

CONSTITUTION: A heavy load and high-speed radial tire is provided with belts 3 between a carcass 1 and a tread 2, and the tread 2 is divided into a tread- central part and tread side parts 5. In this case, in the tread-central part 4, a ground contact width S ranging 30 to 85% of the ground contact width W at the time when a regual load is applied, is provided around the tire-equatorial plane. Further, the tread-central part 4 is constituted by a rubber-composite where a rubber in which a ratio of mixed rubber such as natural rubber, etc., to poly-butadiene rubber ranges from 80/20 to O/100 is blended. Furthermore, the tread side part 5 is constituted by a rubber-composite where a rubber in which a ratio of mixed rubber such as natural rubber, etc., to poly-butadiene rubber ranges from 100/0 to 80/20, and a rubber mixed with a rubber selected from a group of specific rubbers, are blended.