Polysomnography (PSG) was recognized as gold standard for diagnosing OSA. However, for pediatric OSA, there exists dispute on the PSG diagnostic criteria. The American Thoracic Society standard (ATS) treated children with AHI > 5/H or obstructive apnea index (OAI) > 1/H as abnormal, while the International Classification of Sleep Disorder standard (ICSD-3) used obstructive apnea-hypopnea index (OAHI) ≥ 1/H. Due to the differences of the above criteria, there were a set of children whose diagnoses were controversial, making the treatment decision rather thorny.