Abstract: Dissimilar 5083-6082 Al-Alloys in 4 mm thickness were successfully friction stir welded. The metallographic observation demonstrates that the dynamic recrystallization occurred in the weld nugget,which consists of refined equiaxed grains. Mechanical tests demonstrate that the joint in which 6082 Al-Alloy was located on advancing side shows a higher tensile strength than that of 5083 Al-Alloy on advancing side;the angles upon face and root bend tests attains to 180°.