A pneumatic radial tire for a passenger car comprising a carcass having a radial structure, a belt layer arranged on an outer side of the carcass and formed of at least two belt plies (7A, 7B), and a tread portion whose position when mounted on a vehicle is specified, wherein the tread portion has an outer tread edge (To) and an inner tread edge (Ti) respectively located, when the tire is mounted on a vehicle, on an outer side and an inner side of the vehicle, the tread portion has a tread pattern formed in an asymmetric shape with respect to a tire equator, the tread portion is divided into a plurality of circumferential land regions by a plurality of main grooves extending continuously in a tire circumferential direction, the circumferential land regions include an outer shoulder land region including the outer tread edge (To), an inner shoulder land region including the inner tread edge (Ti), and at least one middle land region arranged therebetween, the outer shoulder land region is larger than the inner shoulder land region with respect to rigidity in the tire circumferential direction and the rigidity in a tire axial direction, the outer shoulder land region is provided with a plurality of outer shoulder lateral grooves extending axially inwardly from the outer tread edge (To) and terminating within the outer shoulder land region, the inner shoulder land region is provided with a plurality of inner shoulder lateral grooves extending axially inwardly from the inner tread edge (Ti) and terminating within the inner shoulder land region, and a number of the inner shoulder lateral grooves is not less than 1.1 times a number of the outer shoulder lateral grooves, characterized in that an angle (θ4) of each of the outer shoulder lateral grooves with respect to the tire axial direction is smaller than an angle (θ1) of each of the inner shoulder lateral grooves with respect to the tire axial direction. the tread portion has an outer tread edge (To) and an inner tread edge (Ti) respectively located, when the tire is mounted on a vehicle, on an outer side and an inner side of the vehicle, the tread portion has a tread pattern formed in an asymmetric shape with respect to a tire equator, the tread portion is divided into a plurality of circumferential land regions by a plurality of main grooves extending continuously in a tire circumferential direction, the circumferential land regions include an outer shoulder land region including the outer tread edge (To), an inner shoulder land region including the inner tread edge (Ti), and at least one middle land region arranged therebetween, the outer shoulder land region is larger than the inner shoulder land region with respect to rigidity in the tire circumferential direction and the rigidity in a tire axial direction, the outer shoulder land region is provided with a plurality of outer shoulder lateral grooves extending axially inwardly from the outer tread edge (To) and terminating within the outer shoulder land region, the inner shoulder land region is provided with a plurality of inner shoulder lateral grooves extending axially inwardly from the inner tread edge (Ti) and terminating within the inner shoulder land region, and a number of the inner shoulder lateral grooves is not less than 1.1 times a number of the outer shoulder lateral grooves, characterized in that an angle (θ4) of each of the outer shoulder lateral grooves with respect to the tire axial direction is smaller than an angle (θ1) of each of the inner shoulder lateral grooves with respect to the tire axial direction.