HEAVY DUTY PNEUMATIC TIRE

A heavy-duty pneumatic tire having block land portions in a tread surface can reduce the tire circumferential shearing strain and heat generation in the tread portion to prevent the separation failure between the tread rubber and the belt more effectively. A heavy-duty pneumatic tire has, in a tread surface, blocks defined by a plurality of circumferential main grooves each continuously extending in a tire circumferential direction and a plurality of transverse grooves each communicating between circumferential main grooves adjacent in a tire width direction, wherein in a tire widthwise area that centers on a tire equator and whose width in the tire width direction is 50% of a tread width: at least one of the blocks has a block partitioning groove that is open to each of transverse grooves defining the block and is shallower than the circumferential main grooves, to divide the block into a plurality of small blocks; and at least one of the small blocks has a block auxiliary groove that is open to the block partitioning groove at one end and open to a corresponding circumferential main groove or transverse groove at an other end and is shallower than the circumferential main grooves.