Objective:To explore the factors influencing the pulmonary function of persons with mild to moderate adolescent idiopathic scoliosis (AIS).Methods:Forty-four persons with AIS were tested for their pulmonary ventilation functioning. The indicators were the percentage of forced vital capacity (FVC%), the percentage of forced expiratory volume in the first second (FEV1%) and the percentage of maximum chase volume (MVV%). Data including age, gender, course of disease, dancing habits, exercise habits, body mass index (BMI), Cobb angle, rotation angle, diaphragm thickness, and diaphragm excursion (DE) were also collected. Linear regressions were evaluated to analyze the factors best predicting pulmonary functioning. Spearman correlation coefficients were computed to quantify the correlation between respiratory muscle functioning and pulmonary functioning.Results:The univariate analysis showed that dancing and DE independently influence FVC%, FEV1%, and MVV%. DE was the only independent factor significantly predicting pulmonary functioning for mild to moderate AIS patients. DE was also significantly positively correlated with average FVC%, FEV1% and MVV%.Conclusions:Respiratory training aimed at enhancing DE is necessary to improve the pulmonary ventilation of persons with AIS.