A wheel bearing device having a unitized hub ring, double-row bearing and constant velocity universal joint with one of double-row inner raceways formed on the joint outer ring. An end portion of the joint outer ring is fitted to an outside periphery of the hub ring through serrated portions. The hub ring is plastically deformed and expanded from an inside diameter side toward an outside diameter side by pushing a steel ball into a through hole of the hub ring preventing play in the serrated portions by the diameter expansion. A surface-hardened layer is formed at least on a base portion of the wheel mounting flange.