Objectives: Determine the rate of eustachian tube ventilation dysfunction in chronic otitis media with perforated tympanic membrane, the rate of change ventilatory function of eustachian tube after medical treatment and correlation between clinical an.{i ventilatory function of eustachian tube. Method: Prospective studies describes case series in 105 patients with chronic otitis media with perforated tympanic membrane at the Eyes - Ear Nose Throat - Stomatology An Giang Hospital from 10/2011 to 3/2013. Results and comment: In chronic otitis media with perforated tympanic membrane, the rate of eustachian tube ventilation dysfunction is quite high. The rate of obstructed eustachian tube in discharged ears is higher dry ear. The longer disease duration and the larger tympanic membrane size, the higher obstructed eustachian tube rate. No correlation between ventilatory condition of eustachian tube and position of eardrum perforation. Conclusion: The rate of eustachian tube ventilation dysfunction in chronic otitis media with perforated tympanic membrane is 67,5 percent. After medical treatment, 53,1 percent ears changes from obstructed to open eustachian tube. Correlation between ventilatory condition of eustachian tube and disease duration. Difference between tympanic membrane size and ventilatory condition of eustachian tube.