PURPOSE: To obtain an excellently durable, pneumatic ultra flat radial tire without decreasing the molding efficiency by specifying its compression in the turn-up end of a carcass extending to both the ends of a belt and overlapping the belt.

CONSTITUTION: The pneumatic radial tire, so called, for 50 series passenger car is of the kind where the tire size is 205/50VR16 and the compression is 60 or lower, and spread over between the bead cores 3 is a carcass consisting of a polyester code arranged at almost 90° with respect to the tire peripheral direction of a pair of bead cores 3, and both the ends are wrapped around and engage to the bead cores. Across belt 5 having codes being crossed each other in its interlayer is arranged, consisting of two layers of steel codes being inclined about at 18 degrees with respect to the tire peripheral direction in the radially directional outside of the crown part 9 of a radial carcass.