Myringoplasty was introduced by Berthold in 1878 but the modern era of tympanoplasty did not begin until the 1950's with the work of Zollner and Wullstein. Success rates in the range of 90% are frequently quoted. Despite the high success rate, the effect of many influencing factors remains unresolved. Poor eustachian tube function and prevalence of infectious ear disease are thought to be the reasons for less successful outcome associated with tympanoplasty. In has been well known that a well functioning eustachian tube is an essential prerequisite for successful outcome. We clinically studied the relationship between the eustachian tube function and condition of aditus ad antrum which is the second bottle neck to mastoid air cell using 73 patients who have perforated chronic otitis media without cholesteatoma. There was statistically significant correlation between the eustachian tube function and condition of aditus ad antrum(p<0.01).