The purposes of operative treatment in unstable thoracolumbar and lumbar spine fractures are anatomical reduction and stabilization of the fractures and thus promote neurological recovery and early rehabilitation. To achieve these goals, complete preoperative assessment and recognition of the fracture pattern is necessary in addition to good surgical technique. The authors analyzed 47 cases of thoracolumbar and lumbar spine fractures operated from Jan. 1989 to Dec. 1991 at the Department of Orthopaedic Surgery, National Medical Center. All cases were classified according to Denis classification and in deciding the appropriate surgical approach, fracture type, stability, neurologic status and degree of deformity were all considered. Anterior approaches were performed in 23 cases of burst fracture and 3 cases of fracture-dislocation, and posterior approaches were performed in 1 case of compression fracture, 7 cases of burst fracture, 4 cases of seat-belt type injury and 5 cases of fracture-dislocation, In 3 cases of burst fracture and 1 case of fracture-dislocation, both anterior and posterior approaches were combined. With the analysis of postoperative changes in sagittal and coronal angle, translation and degree of rotation, we evaluated the results of operative reduction in terms of restoring normal anatomical configuration of injured spinal segments. So we tried to find the attributing factors in the operative reduction of the thoracolumbar and lumbar spine fractures and suggest the proper surgical approach that provides better reduction and stabilization.