In the present study, we aimed to examine the effects of Schroth exercise(three-dimensional convergence exercise) on pulmonary function(vital capacity, and chest expansion), Cobb`s angle, scoliometer angle, and erector spinae muscle activity. We examined 40 students with idiopathic scoliosis(Cobb`s angle ). They were divided into the Schroth and conventional exercise groups, with 20 people in each group. Statistical analysis was performed by using SPSS 18.0 with a paired t-test(pre-post difference) and an independent t-test(between-group differnence). the result of were as follows; 1) After 8 weeks of Schroth exercise, significant improvements were observed in Cobb`s angle, rib hump, vital capacity, chest expansion, and right thoracic longissimus muscle activity. 2) After 8 weeks of conventional exercise, a significant improvement was observed only in chest expansion. These findings indicate that the Schroth exercise program improved the Cobb`s angle, rib hump, pulmonary function, and sEMG results. Therefore, this study demonstrates the usefulness of the Schroth exercise program for idiopathic scoliosis.