A method of manufacturing a wheel rim for a motor vehicle comprises the steps of a strip of aluminum alloy sheet material having a predetermined cross-section suitable for forming into a wheel rim by extrusion molding, pressing the strip step-by-step lengthwise by an upper mold and a lower mold having complimentary profiles for causing the strip to have predetermined profiles as a hoop with a formed gap between the both ends, welding the gap to form an unfinished wheel rim, and annealing, shaping, heat treating, and polishing the unfinished wheel rim to form a finished wheel rim.