To study ventilatory function of the Eustachian tube at normobaric state in sports SCUBA divers who are frequently exposed to hyperbaric condition, have to actively inflate the Eustachian tube to adjust surrounding pressure, authors evaluated 116 ears of 58 SCUBA divers through modified 9 step method with tympanometry and we also evaluated the influential factors of some diving variable such as age, sex, duration, total number, frequency, mean depth and usual activity of diving to the tubal function. Diver group showed significantly higher rate of the Eustachian dysfunction(69.0%) than that of control group(46.4%). Age and mean depth of diving effect, not significantly, to the ventilatory function. In middle ear pressure change, diver group showed smaller change of pressure in all four maneuvers, Valsalve, Toynbee, inflation and deflation maneuver compared to contro group but significantly only in valsalve maneuver. Age significantly affect but duration, total number of diving and sex affect, not significantly,  to the middle ear pressure change. We concluded that ventilatory function of the Eustachian tube at normobaric condition in sports SCUBA divers is significantly worse than that of normal and the older the divers, the worse the ventilatory function.