Abstract: Objective：To investigate the clinical efficacy of preoperative Halo gravity traction in the treatment of severe adolescent scoliosis. Methods：The clinical data of 37 cases of severe scoliosis in adolescents admitted to Department of Spine Surgery, Changzheng Hospital from January 2009 to December 2014 were retrospectively analyzed. All patients received Halo gravity traction before operation, and the followup time ranged from 1 to 4 months. Results：Compared with before traction, forced vital capacity (FVC) increased significantly (［1.97±0.35］ L vs ［2.34±0.22］ L), forced expiratory volume in one second (FEV1) increased significantly (［1.75±0.28］ L vs ［2.08±0.15］ L）, plasma albumin increased significantly （［33±9］ g/L vs ［38±3］ g/L）, and the differences were all statistically significant (P<0.01). The change of main curve before and after traction was positively correlated with FVC change (r=0.230, P=0.004) and FEV1 change (r=0.216, P=0.007). During the traction, 1 patient experienced transient brachial plexus palsy. Conclusions：Preoperative Halo gravity traction can gradually correct the spinal deformity, enhance the pulmonary function, and improve the nutrition level of adolescent patients with severe scoliosis. But tractionrelated neurological complications should be prevented.