Abstract: The microstructures, microhardnesses, tensile properties and fracture morphologies of aluminum alloys without Er or with Er annealed at different temperatures were compared and analyzed. The results showed that at the same annealing temperature, the microhardness of aluminum alloy containing Er was higher than that of aluminum alloy without Er and the tensile strength and yield strength of aluminum alloy containing Er were both higher than those of aluminum alloy without Er; The recrystallization temperature of aluminum alloy containing Er obviously improved compared with that of aluminum alloy without Er, which were mainly related to the formation of nanoscale Al₃Er or Al₃ (Zr, Er) particles coherent or semi coherent with the matrix when Er element was added in the alloy.