Eventhough Cholesteatom was found in 1828 by Johanes Mueller but Pathogenic mechanism has been only known as theory. Cholesteatomas that arise from refraction pockets are known as primary acquired cholesteatoma. Several theories have been advanced to explain the formation of primary acquired or attic refrection Cholesteatomas including invagination of the pars jlaccida, basal cell hyperplasia, otitis media with effusion, and perforation of the pars jlaccida membrane with epithelial ingrowth. Studying 86 patiens suffer from otitis of closed tympanic membrance with comperating betweent the results of endoscopy, tympanograms and surgery. The study suggests: it is chronic injlammations of the nasopharyn cavum (VA, chronic sinusitis or cancer of nasopharyn) may be the cause of the otitis media with effusion and the Cholesteatomas of retraction pocked.