An pneumatic radial tire for a passenger car having an improved durability, which tire has a carcass layer formed of aromatic plyamide cords in which an end portion of the carcass layer is turned up around an annular bead wire and a lower bead filler from the inside to the outside of the tire to form a turnup portion which is extended along the main body of the carcass layer, wherein an upper bead filler having a JIS hardness of from 75 to 95 is disposed axially outside the turnup portion, and wherein the height b (mm) of the lower bead filler relative to the height a (mm) of a rim flange upon which the tire is mounted satisfies the formula:(a-5)