A high electrical resistance, superior formability aluminum alloy useful as structural materials used in structures suffering the action of high magnetic field, nuclear fusion reactor or the like, said aluminum alloy consisting essentially of, by weight, 1.0 to 8.0% of Mg, 0.05 to less than 1.0% of Li, at least one element selected from the group consisting of 0.05 to 0.20% of Ti, 0.05 to 0.40% of Cr, 0.05 to 0.30% of Zr, 0.05 to 0.35% of V, 0.05 to 0.30% of W and 0.05 to 2.0% of Mn, and the balance being aluminum and incidental impurities. Further, Bi in the range of 0.05 to 0.50 wt. % may be contained in said alloy.