Abstract: Superplastic aluminum alloy strips comprising 1.5 to 90% of magnesium, 0.5 to 5.0% of silicon, 0.05 to 1.2% of manganese, 0.05 to 0.3% of chromium and the balance consisting essentially of aluminum, and also a process for producing superplastic aluminum alloy strips comprising continuously casting and rolling a molten aluminum alloy containing 1.5 to 9.0% of magnesium, 0.5 to 5.0% of silicon, 0.05 to 1.2% of manganese and 0.05 to 0.3% of chromium, thereby obtaining a cast strip of 3 to 20 mm in thickness, homogenizing the cast strip at a temperature of 430.degree. to 550.degree. C., and subjecting the homogenized strip to cold rolling until the reduction ratio reaches up to a value of not less than 60%.