There is provide a pneumatic radial tire for heavy loads capable of more effectively preventing a breakdown due to separation of a rubber chafer in an area corresponding to a bead heal portion than before. A pneumatic radial tire 10 for heavy loads has a pair of bead portions 12, a bead core 14 which is embedded in each of the bead portions 12, a radial carcass 16 extending from one bead portion 12 to the other bead portion 12 and turned around the bead core 14 from an inner side to an outer side of the bead portion 12 in a width direction of the tire to be anchored, a rubber chafer 22 disposed over the radial carcass 16 in the opposite side of the bead core 14. An angle θ formed by a steel cord 24S of the wire chafer 24 provided inside of the bead portion 12 outside of the radial carcass 16 and a carcass ply cord 16S of the radial carcass 16 is optimized depending on shear strain generated in the rubber chafer 22 so as to effectively preventing a breakdown of the rubber chafer 22 due to separation in an area corresponding to a bead heal portion 26.