the invention relates to a radial tire in which each sidewall covering and protecting the side face of the carcass is composed of a plurality of layers differing in rubber composition . in the radial tire according to the invention , the sidewall has a three - layer structure consisting of an adjesive layer adjacent to the carcass , an inner layer disposed outwardly thereon and an outer layer disposed further outwardly thereon . the rubber components in the rubber compositions respectively constituting the three layers differ in proportions of the rubber having as low degree of unsaturation and the rubber having a high degree of unsaturation and the high - unsaturation rubber content decreases in the order of adhesive layer , inner layer and out layer . while retaining the endurance characteristics and ozone resistance of the conventional tires , the radial tire according to the invention is improved in that its good appearance can be prevented from being spoiled by staining or discoloration of its side portions . in spite of the use of rubbers having a low degree of unsaturation , the invention provides a radial tire having sidewalls excellent in adhesiveness to the carcass and other portions made of a diene rubber composition .