A Group(236cases) was treated with tonsillectomy and adenoidectomy was compared with another group(control group, 110cases) of normal child visited at the pediatric well baby clinic about the morbidity of OME. The following are the results. 1) The comparison of the morbidity between T & A Group(Group A) and normal Group(Group B) showed that the Group A was 66cases of 236cases(28%) and the Group B was 17cases of 11cases(16%). 2) The incidance of OME in age distribution was that the Group A was 45cases(68%) between 5 and 7 years in male, 14cases(22%) between 5 and 6 years in female and the Group B was 4cases(26%) of 3 years children in male, and 6cases of the 4 years in female. 3) The seasonal distribution of the OME showed that the high peaked incidance was cool season, winter(11.12.1.2 month). 4) The relationships between OME and T & A was guessed that the children treated with tonsillectomy and adenoidectomy were improved for symptoms of OME about 90% more.