The influences of rare earth elements (cerium and lanthanum) on the microstructure and phases ofAl-3.0 wt％Mg alloys used for electromagnetic shielding wire were characterized by scanning electron microscopy (SEM),energy-dispersive spectroscopy (EDS),X-ray diffraction (XRD) and differential scanning calorimetry (DSC).The mechanical properties and electrical resistivity were also investigated.The results indicated that a certain content of rare earth could improve the purification of the aluminum molten,enhance the strength,and reduce the electrical resistivity ofAl-3.0 wt％Mg alloys.The strength reached the top value when RE content was 0.3 wt％ while the alloy with 0.2 wt％ RE addition had the smallest electrical resistivity.The elongation varied little when RE addition was no more than 0.2 wt％.But the excessive addition of rare earth would be harmful to the microstructure and properties ofAl-3.0 wt％Mg alloys.