Objective: This study aims to evaluate the efficacy of specific exercise therapy for the treatment of skeletally immature idiopathic scoliosis (IS). Methods: A total of 51 mild IS patients receiving specific exercise therapy in Guangdong Xinmiao Scoliosis Prevention Center from October 2017 to September 2021 were recruited in this study. Treatment outcome were evaluated at 1 year follow up. All the participants were divided into two groups: open ( n =32) and closed triradiate cartilage group ( n =19), and outcome of treatment were compared within the two groups. Results: After (26.5±9.8) months of treatment, the Cobb angle of the major curve was corrected from an average of (15.5±4.2)° to (11.3±6.7)°, with an average correction of (4.5±5.7)°. Among them, 58.9% patients achieved improvement in the major curve Cobb angle, 33.3% achieved stabilization, and 7.8% progressed. There was no significant difference in the major curve Cobb angle between the closed and open triradiate cartilage groups before treatment( t =-0.73, P =0.47), whereas there was a significant difference in the correction of the major curve after treatment( t =-2.73 , P <0.05). Conclusion Specific exercise therapy effectively prevents the progression or corrects the scoliosis in patients with skeletally immature idiopathic scoliosis. It s more effective in patients with open triradiate cartilage than in those with closed triradiate cartilage.