A wheel bearing apparatus has an outer member, an inner member, and double row rolling elements are contained between the outer raceway surfaces. Seals are mounted in openings formed between the outer member and the inner member. A shoulder height H of the inner raceway surface of the inner ring is set with a range of 0.4-0.8 times a diameter “d” of the ball (H/d=0.4-0.8). A shoulder height δ of a smaller diameter portion formed on the outermost circumference of the inner ring is set to a value δ/d≧0.35. A corner, formed by the tapered surface and the inner raceway surface, is rounded to have a circular arc cross-section. A shoulder height H1 of the inner raceway surface from its bottom to the corner is set within a range of 0.40-0.50 times a diameter of the ball (d) (H1/d=0.40-0.50).