Abstract: Objective: To compare the efficacy of unilateral tonsillectomy + adenoidectomy with the efficacy of bilateral tonsillectomy + adenoidectomy in treatment of children with obstructive sleep apnea hypopnea syndrome(OSAHS). Methods: Ninety-six cases with OSAHS children were randomly divided into two groups,group A underwent bilateral tonsillectomy + adenoidectomy,group B underwent unilateral tonsillectomy + adenoidectomy (modified group). Results: The patients were followed up six month to one year after the operation,there were no significant difference between two groups in treating the OSAHS(P > 0.05). The surgical approach of group B did not affect the curative effect on the children with OSAHS. Conclusions: The unilateral tonsillectomy + adenoidectomy could not only retain the physiological function of children's unilateral tonsil,but also treat the OSAHS effectively,which is an operation methord worth of promoting.