An aluminum alloy containing magnesium (Mg) between 3.0 and 4.0 wt. %, manganese (Mn) between 0.5 and 1.0 wt. %, copper (Cu) between 0.2 and 0.6 wt. %, iron (Fe) between 0.05 and 0.4 wt. % and remaining obligatory trace elements, has an electrical conductivity after baking of 30 to 32% IACS, a yield strength of 320 MPa or more and a ratio of decrease in buckling strength after retort-treatment to that immediately after manufacturing the can end of less than 10%. This an aluminum alloy sheet for can ends has an excellent corrosion resistance, complete lack of stress corrosion cracking, or age softening resistance, maintains the a high buckling strength obtained subsequent to the manufacture of a can, even after retort treatment and storage at room temperature. The aluminum alloy sheet of this invention is particularly suitable for use as a can end for non-carbonated beverages and has the potential for even thinner aluminum alloy sheet formation.