This study was performed by the necessity of objective information upon change of pulmonary function after surgical correction of spinal deformity in scoliotic patients. It is relatively well known that deformity of spinal curvature affects the pulmonary functions, especially lung volume or vital capacity, due to restriction of the thoracic cage. It is carried out the comparative study between preoperative and postoperative pulmonary functions in thirty two cases of thoracic scoliosis, all who were treated with Harrington instrumentation and posterior fusion at Department of Orthopedic Surgery, Seoul, National University Hospital from 1969 to 1983. The age distribution of patients was from 6 years to 21 years and female was more involved two times than male. Following observations were obtained: Following observations were obtained: 1. Pre-and postoperative angle of scoliosis were 77.5° and 39.2° with correction rate of 48.2%. 2. Preoperative vital capacity was 64.2% and postoperative value was 74.8%, 2 years and 2 months after operation in average. 3. Postoperative vital capacity was significantly increased compared to preoperative value in patients with scoliosis (p<0.05). 4. Ther was no definite pattern of obstructive pulmonary disease in patients with scoliotic deformity.