PURPOSE: To manufacture the rim with excellent mechanical strength, by forging the cylindrical blank of aluminum alloy to form the preparatory rim body.

CONSTITUTION: The thick walled cylindrical blank M of aluminum alloy is pressure formed by forging work into a preparatory rim body R1, being provided with approximate T-type section, consisting of the connecting flange 3 for the wheel disk at the inner side in the radial direction, the front rim 1 being thin walled in the direction of axis of the cylinder taking the flange 3 as the boundary, and the rear rim 2. Next, the front rim and the rear rim of the preparatory rim body R1, are pressed to deform the preparatory body R1 into the shape of approximately Y-type section. After that, the front and rear rims of the preparatory body R1 are spun so as to be more thinned and formed into the final sectional shape of the expected rim R2. Since the preparatory body is formed by the forging work, the material flow is endowed with a constant directional property, and is fibered compactly.