To determine postoperative maintenance of correctability between Harrington instrumentation and transpedicular screw fixation for unstable thoracolumbar spine fractures, the authors analysed 50 patients who were operated from 1983 to 1991. Twenty eight of fifty patients were treated with Harrington instrumentation and rest of them with transpedicular screw fixation. The results were as follows: l. According to the Denis classification, bursting type B fracture was the most common (48%). 2. In Harrington instrumentation, average preoperative kyphosis angle was 21.6 degrees and immediate postoperative kyphosis angle was 10.3 degrees with 11.3 degrees of correction. There was 4.7 degrees of loss of correction with an average follow-up of 45 months. 3. In transpedicular screw fixation, average preoperative kyphosis angle was 17.7 degrees and immediate postoperative kyphosis angle was 11.4 degrees with 6.3 degrees of correction. There was 3.6 degrees of loss of correction with an average follow-up 27 months. 4. In Harrington instrumentation, average preoperative anterior and posterior vertebral heights were 58.2 (%) and 103.9 (%) and immediate postoperative anterior and post-erior vertebral heights were 83.9 (%) and 103.6 (%) with 25.7 (%) and 0.3 (%) of correction. There were 4.6 (%) and 2.9 (%) of loss of corrections with an average follow-up of 45 months. 5. In transpedicular screw fixation, average preoperative anterior and posterior vertebral heights were 57.9 (%) and 97.6 (%) and immediate postoperative anterior and posterior vertebral heights were 88.7 (%) and 101.5 (%) with 30.8 (%) and 3.9 (%) of correction. There were 4.6 (%) and 3.1 (%) of loss of corrections with an average follow-up of 27 months. 6. The average fused segments were 5.9 in Harrington instrumentation and 3.1 in transpedicular screw fixation respectively.