To provide an automobile wheel disc that is provided with a projecting shape effective in improving spoke rigidity and durability while the durability of the interface between the projecting shape and the hub mounting part is ensured, with which the number and arrangement of the spokes and hub mounting bolt holes do not limit each other, and that facilitates the hub nut tightening operation.

The wheel disc has connecting walls 16 that connect a pair of spokes 13 positioned on both sides, in the wheel radial direction, of an ornamental hole 15 on the inside, in the wheel radial direction, from the disc periphery 14. The connecting wall 16 has a projecting wall top part 16c, in the wheel radial direction, that extends to the hub mounting part 12 from an ornamental hole edge curved part 16b positioned on the inside, in the wheel radial direction, from the ornamental hole 15. The cross-sectional shape of the projecting wall top part 16c, cut in a plane perpendicular to the wheel shaft center, is configured by a straight line, or an arc or an ellipse having a larger curvature radius than the curvature radius of spoke reinforcing plates 13b2 positioned on both sides of the projecting wall top part 16c.