Abstract: According to the traditional way of classification, the effect of rare earths on aluminium alloys is summarized systematically. The research of rare-earth Aluminium alloy focused on La, Ce, Y and mischmetal in the past, the effect of the other rare earths on aluminium (such as strengthening tougheness, corrosion resistance and weldability) has seldom been researched. The research group including the author observed deeply the effect of the different rare-earth element on aluminium alloys and discovered that the rare-earth element Er has remarkable effect on aluminium alloys. Er element not only can make the crystal particle of aluminium alloy become finer, but also can enhance the strong tonghness and corrosion resistance. Therefore, it is necessary to investigate Er-doped aluminium alloys intensively and extensively.