The purpose of this research is to investigate effect of rare-earth elements (Y and Dy) on industrial pure Mg through the ignition point test and oxide film analysis. The results show that the 0.5%Y can make the ignition point of pure magnesium about 30°C higher. However, the ignition point of pure magnesium can be multiplied about 50°C by the mixed additions of 0.5wt%Y and 5wt%Dy. The SEM analysis indicates the oxide film of Mg-0.5Y-5Dy is more compact and tenacious than that of Mg-0.5Y. The XRD analysis indicates that the oxide film of Mg-0.5Y-5Dy consists of MgO, Y2O3 and Dy2O3. The most of all the three oxides are Dy2O3, which can prevent magnesium from further oxidizing.