Objective:To investigate the efficacy of allograft bone in posterior spinal fusion in thoracolumbar fracture. Methods:33 patients with thoracolumbar fracture,who underwent posterior spinal instrumentation and fusion using allograft or autograft bone,were evaluated prospectively. All of the patients were randomized into group A(16 cases using only allograft bone)and group B(17 cases using only autograft iliac bone). The mean operative duration,average blood loss and complications between the two groups were analyzed comparatively. Fusion rate and Oswestry score at 24 weeks after surgery of the 2 groups were calculated respectively. Results:Group A was better than group B by a shorter operative duration,less blood loss. Fusion rate at 24 weeks after surgery of the two groups was 100%. There was no significant difference of Oswestry score at 24 weeks after surgery between the 2 groups. Conclusion:A satisfactory outcome can be achieved in posterior spinal fusion in thoracolumbar fracture using allograft bone.