Objective To study the influence of calcium phosphating temperature and time on the structure and property of phosphating film on magnesium alloys. Methods By controlling the single factor variables, the magnesium alloys were phosphated under the condition of different phosphating temperature and time. The morphology, structure and properties of phosphating film were analyzed by scanning electron microscope (SEM), X-ray diffraction (XRD) and polarization curve test respectively. Results SEM showed that the crystal shape of the phosphating film looked like petals, whose main composition was CaHPO4·2H2O. The phosphating film became thick with the phosphating time increasing, but its flatness became bad. The polarization curve test showed when phosphating time was 30 minutes, the corrosion potential and polarization resistance of the phosphating film were maximum, the corrosion current density was minimum, and the corrosion resistance was the best. The result of SEM showed the density of phosphating film was the best at 30 ℃ phosphating temperature. The XRD result showed that the crystallinity and coverage of phosphating film were the best at 30 ℃. What’s more, its polarization resistance was maximum, the corrosion current density was minimum, the phosphating film had the best corrosion resistance. Conclusion The quality and corrosion resistance of phosphating films become the best at 30 ℃ when the phosphating time is 30 min.