Objective To study the degradation behavior and mechanical properties of magnesium alloy plate on treatment of tibial fracture in New Zealand rabbits. Methods 36 adult New Zealand rabbits were randomly divided into experimental group (magnesium alloy plate group) and control group (titanium alloy plate group). Tibial fractures in experimental group and control group were fixed with magnesium alloy plate and titanium alloy plate respectively. After operation, X-ray, scanning electron microscopy, energy spectrum analysis, weight loss test and four-point bending test were performed in each group to analyze the the degradation behavior and mechanical properties of magnesium alloy plate on treatment of tibial fracture in New Zealand rabbits. Results X-ray showed that magnesium alloy plate can be degraded gradually in vivo. Scanning electron microscope, energy spectrum analysis and weight loss test results showed that the degradation of magnesium alloy plate was deepened gradually with the implantation time, and the surface was corroded uniformly. The four-point bending test results showed that the mechanical properties of magnesium alloy plate decreased gradually with the degradation in vivo. Conclusion Magnesium alloy plate can be degraded gradually in the process of fracture healing, and its mechanical properties weaken gradually during the degradation in vivo.