Scandium microalloying aluminum alloy is a kind of new material. Scandium is considered to be the best alloy strengthening element for aluminum alloys at present. The addition of scandium to aluminum alloy forms Al3Sc particles and produces a strong microalloying effect, which can improve the properties of aluminum alloy in an all-round way. Scandium microalloying aluminum alloy is considered to be a high performance alloy material for the new generation of aerospace, ship, weapons and so on .The physical metallurgical behaviors and performances were summarized in this paper, such as obviously grain refining, intensively precipitation strengthening, recrystallization inhibiting and so forth. The improvements of Sc on the properties of Al alloys, such as comprehensive mechanical properties, corrosion resistance, weldability and so on, were introduced. Based on the international and domestic researches, the paper discussed the development trends in this field.