Snoring and sleep apnea are caused by structural narrowing of the upper airway and the loss of functional muscle tone during sleep. Snoring in children is caused mainly by chronic tonsillar hypertrophy and/or adenoid vegetation. The morphologic characteristics specific to the obstructive sleep apnea patients have been studied recently and some variables even can be considered as the parameters of obstructive sleep apnea syndrome. We evaluated the snoring grade, noise level during sleep, the lowest O₂ saturation during sleep, adenoid-nasopharyngeal(AN) ratio, palatine tonsillar hypertrophy(PTH) and body mass index(BMI) of the patients who have been hospitalized to the department of otorhinolaryngology, Seoul National University Hospital under the diagnosis of chronic tonsillitis and/or adenoid vegetation. The patients were grouped according to snoring grades, and we compared them with the values of noise level, the lowest O₂ saturation, adenoidonasopharyngeal ratio, degrees of palatine tonsillar hypertrophy and body mass index. The cephalometric evaluation of the patients was done concomitantly including SNA, SNB, PAS, SN, LFH and BaPns, and it was assessed for correlation with snoring grades(Fig.3). The values of the noise level, lowest O₂ saturation and AN ratio showed statistically significant correlations with snoring grades, but the PTH and BMI showed no statically significant correlations with snoring grades. In the cephalometric evaluation, the parameters showed no significant statistical correlation with the snoring grade except BaPns(distance between basion and posterior nasal spine).