Segmental wiring to treat the unstable fracture and fracture-dislocation of the thoraco-lumbar spine is more effective method than Harrington instrumentation as primary procedure which afforded immediate rigid internal fixation of the spine and permitted mobilization without external support and immediate rehabilitation. A clinical study was made of twenty seven patients who were hospitalized and treated at the Department of Orthopaedic Surgery, Wonju Christian Hospital from Feb. 1979 to Apr. 1983. The following results were obtained: l. Of twenty seven patients, nine(33.3%) had a flexion rotation, eight(29.6%) had a shearing, eight (29. 6%) had a flexion compression and two(7.5%) had a vertical compression by Holdsworths mechanism of injury and by Pauls classification of fracture, thirteen(48. 1%) had a flexion distraction fracture, twelve(44. 4%) had a translation fracture and two(7. 5%,) had a unstable burst fracture. 2. Fifteen(55. 6%) had a complete neural deficit and five(18. 5%,) had an incomplete neural deficit. Six(22.2%) of the fifteen patients with complete neural deficit and one(3. 7%.) of the five patients with incomplete neural deficit showed slight neurological recovery, but eight(29.6%) gained complete recovery. 3. Correction of kyphotic deformity was average 12. 4 degree in Harrington instrumentation and average 18. 0 degree in segmental wiring, and during the follow-up periods, there was a final loss of 6. 3 degrees of kyphotic correction in Harrington instrumentation and 3. 0 degrees in segmental wiring. 4. In external support, fourteen(51.9%) had body jacket cast and four(14.8%) had back brace in Harrington instrumentation, but all patients except one brace had no external support in segmental wiring. 5. In complication, two hook dislocations and two pseudoarthroses were occurred in Harrington instrumentation, but any complication except only one cases of wound infection was not occurred in segmental wiring.