A wheel cover (10) has a plurality of vent holes (15) along an outer peripheral portion of a wheel cover body (11) at positions opposed to solid portions (8) between disc openings (6) in a road wheel (1). An engagement member (12) projects from the edge portion (16) of the vent hole (15), toward the wheel disc (2) of the road wheel (1). A disc-locking portion (18) projects from the tip end portion of the engagement member (12), toward the vent hole (15), and preferably includes locking protrusions (31, 32) engageable with a peripheral portion (7) of the disc opening (6), so that a retainer (24) is engaged with a retainer locking concave portion (35) to urge and hold the disc-locking portion (18).