A pneumatic radial tire having highly durable bead structure is disclosed. One or more carcass ply layers of steel cords are turned up around a bead core from the inside to the outside. A reinforcing strip of steel cords is positioned outwardly adjacent to the turn-ups of carcass plies. A bead filler of approximately triangular sectional shape is disposed at the region enclosed by the carcass plies, the turn-ups of the carcass plies and the reinforcing strip of steel cords. The bead filler comprises high hardness rubber stock and medium hardness rubber stock. A cap of organic textile cord fabric covers an upper end of the reinforcing strip of steel cords. A fin-shaped rubber buffer having a hardness lower than that of the medium hardness rubber stock by 3 DEG to 20 DEG is disposed radially outwardly of the capped end and axially outwardly adjacent to the medium hardness rubber stock. A reinforcing strip of organic textile cords may be further disposed outwardly adjacent to the reinforcing strip of steel cords.
