<p>In this work, the effects of cold rolling and T6 treatment on the microstructures, mechanical properties and corrosion resistance of hot-rolled Al-4Cu-xMg (x = 0, 0.25 and 0.5 wt%) alloy sheets were investigated. After cold rolling, the coarse deformed grains with high-density dislocations were preserved in the three alloys. In contrast, after the T6 treatment, fine equiaxed grains developed due to static recrystallization. The addition of Mg decreased the average grain size and triggered the formation of S’-Al₂CuMg. The increased amount of precipitate and the narrow precipitate-free zone were beneficial for increasing the mechanical strength. The mechanical strength slightly increased after cold rolling because only dislocations were introduced, whereas the mechanical strength significantly increased after T6 treatment because of the sharp refinement of grains and the static precipitation of second phases. The addition of Mg greatly optimized the corrosion resistance, which was mainly attributed to the composite oxides composed of Al₂O₃/Al(OH)₃-MgO. In contrast, the corrosion resistance decreased after cold rolling because high-density dislocations triggered localized corrosion. Moreover, the corrosion resistance decreased continuously after the T6 treatment because the massive amount of precipitates had negative effects on the corrosion resistance. Although the corrosion resistance slightly decreased, the mechanical strength was greatly optimized. Thus, a good balance between the mechanical strength and corrosion resistance was obtained for the Al-4Cu-0.5Mg alloy via cold rolling and T6 treatment.</p>