Abstract: Asteady magnetic field (SMF) was imposed during solidification of pure Mg. The effects of SMF on structure and bio-corrosion behavior of pure Mg were investigated. Results show that no detectable difference can be discerned with regard to the influence of SMF on the macrostructure of pure Mg. The (0002) basal plane replaced the (10 (1) over bar1) pyramidal plane as the primary plane with SMF treatment. The (0002) plane was further intensified with the increase of magnetic field intensity, while the relative intensity of the (10 (1) over bar1) plane became lower and lower. Immersion testing and electrochemical measurements have indicated that the beneficial effect of SMF treatment on the bio-corrosion resistance of pure Mg. The bio-corrosion resistance of pure Mg was further increased as magnetic field intensity increased.