Obstructive sleep apnea(OSA) involves loud snoring, respiratory pauses(apneas) during sleep, oxygen desaturation, and lessened sleep quality. The exact evaluation of the degree of apnea and site of obstruction is essential to the selection of method of treatment and follow up evaluation. Polysomnography(multichannel recordings of numerous physiologic variables) is usually performed and necessary. It is valid and reliable but expensive and impractical for large numbers of patients, and most importantly, can not demonstrate the exact site of the obstruction. We have therefore studied the dynamic anatomic changes which take place in the oroand hypopharynx during awake, supine, and deep breathing using the technique of videofluoroscopy. Out findings demonstrate that the long, hypertrophic soft palate depicts curling movement anteriorly or posteriorly while deep inspiration in OSA patients.