Obstructive sleep apnea (OSA) is a disease characterized by repeated partial or complete upper airway collapse during sleep, accompanied by arousals or oxygen desaturation. It was reported to affect 5.7 %~9.6 % of pediatric population in western countries and 5.5 %~7.8 % in China. Children's physical developing and brain functioning as well as quality of life (QoL) could be greatly impaired if the disease was left untreated. Polysomnography (PSG) was recognized as gold standard for diagnosing OSA. However, for pediatric OSA, there exists dispute on the PSG diagnostic criteria. Pediatric OSA was mostly caused by hypertrophy of adenoid or palatine tonsillar. For those PSG validated patients, nonsurgical management was often prescribed, in addition, surgical intervention, i.e. adenotonsillectomy was also commonly applied and had been proved efficient both in terms of PSG and in terms of symptoms, behaviors and QoL rated by caregivers. However, for children with controversial diagnoses by ATS and ICSD-3, little was known about whether surgical or nonsurgical management was effective. We aim at investigating the effect of adenotonsillectomy versus nonsurgical management on QoL in these subjects. And the hypothesis is that adenotonsillectomy improves QoL better than nonsurgical management in children with controversial diagnoses of OSA by ATS and ICSD-3.