On the forty children, age ranging from 2 years 11 months to 17 years 3 months and diagnosed as having adenoids, the anthor made the epipharynx molds by inserting alginic impression material into their epipharyx under aether narcosis. With the use of these molds the author carried out the morphological study of their epipharynx, and obtained the following results: 1. The mean average of the width of pharyngeal tonsil is 20mm, and in the majority of the children it is wider than the width of adenoid curette. 2. In those children with middle ear disease the width of pharyngeal tonsil is greater than the longitudinal length, and also it is bigger than the width of the same in those children without any disorders in the middle ear. 3. The pharyngeal recess is smaller and shallower than that in the adult autopsy case. This seems to be due to the fact that lymphatic tissue is filling up the pharyngeal recess in children. 4. No variation can be recognized in the length, width and depth of ostium of auditory tube by age, sex, and presence or absence of disease. 5. The distance beween tubal lips in children coincides roughly with that in adult autopsy case. 6. The height, width, and cross-section of the choana in children are about one half to two thirds of those in adult autopsy case. The height is shorter in comparison with the width, resembling the choana of foetus and newborn. However, with advance in age the measurements tend to approach those of adult. 7. The distance between the posterior wall of naso-pharynx and the palate is narrowest at the distance covering 8-12mm from the posterior inferior end of nasal septum. This point corresponds approximately the center of pharyngeal tonsil. 8. The cross-section of the narrowest point in epipharynx is a little over one square centimeter.