Snoring is a very common sleep disorder. Approximate 20~30 percent of population and 40~60 percent of middle and old age population are reported to have symptoms of snoring. Snoring patients do not frequently recognize snoring until spouse or colleague has noticed. Hence, for most people snoring has been not a serious health issue but one of bad sleeping habits. However, it recently draws social attention because most patients with diagnosed "Obstructive Sleep Apnea Syndrome" cased by obstruction of the upper airway are reported snoring. In this point, the author attempts to review the clinical aspects and treatments about snoring and "Obstructive Sleep Apnea Syndrome" in the medical and dental perspective.