Palatopharyngoplasty is widely utilized for the treatment of snoring and obstructive sleep apnea. Treatment of the sleep apnea begins with the presurgical evaluation which includes nasopharyngoscope during Mueller maneuver, cephalometrics, polysomnography, multiple sleep latency test, computerized tomography(CT), magnetic resonance imaging(MRI). But the mechanism of snoring and obstructive sleep apnea has multiple complex causes. There were many difficulties in choosing the patients who would show successful postoperative results by surgery with these evaluation methods. From Nov. 1986 to Feb. 1992, authors performed the soft palate measuring in 74 snoring patients and 61 normal controls. The lengths of retromolar raphe and soft palate arch were measured and calculated the ratio of each other. The results were follows : 1) The mean ratios were 0.24(subjects-male), 0.24(subjects-female), 0.54(controls-male), 0.48(controls-female). 2) Symptom improvements noted 83.8%(62 cases) of snoring, 86.5%(64 cases) of sleep apnea and 71.5%(55 cases) of daytime sleepiness. We considered that soft palate measuring as a preoperative evaluation of palatopharyngoplasty was more effective and easier than any others.