PURPOSE: To provide the method which assures the life of electrodes equiv. to the life of plated steel sheets at the time of resistance welding of aluminum alloy materials coated with pure Al.

CONSTITUTION: The method for joining the Al alloy materials by resistance welding consists in coating one surfaces of the same alloy materials or different alloy materials of Al-2 to 6wt.% Cu alloy, Al-2 to 9wt.% Mg alloy, Al-0.05 to 2.5wt.% Mg-0.05 to 2.5wt.% Si alloy, Al-0.8 to 8wt.% Zn-0.5 to 3wt.% Mg alloy or Al-3 to 8wt.% Zn-0.5 to 3wt.% Mg-0.5 to 3wt.% Cu alloy with pure Al of ≥99wt.% purity at a thickness of 2 to 25% of the sheet thickness of the alloy materials and superposing these coated materials on each other with the surfaces coated with the pure Al positioned on the electrode contact surface side, then subjecting the materials to resistance welding.