The effects of Nd on the corrosion resistant property of as-extruded AZ31 magnesium alloys were investigated by salt spray corrosion and a potentiodynamic scanning method. The micromorphology of the corroded samples of the alloys were studied by scanning electron microscope (SEM), and the phase composition and corrosion products of the alloys were analyzed by X-ray diffractometer (XRD). The results show that Nd addition can obviously improve the corrosion resistance of AZ31 magnesium alloys and the corrosion rate changes with the Nd addition. The result of salt spray corrosion is the same as that of potentiodynamic scanning