The gustatory function tests of chronic otitis media cases showed the loss or changes of gustatory function especially to Quinine (0.03%) at the lateral side of the tongue at the same side, however, this result does not seem to be significant. On the other hand, preoperative and consecutive post-operative gustatory function tests of the radical mastoidectomy cases showed the loss or changes of sense of taste especially to salt (0.85%) and quinine (0.03%) at the same side of the tongue on the first post-operative day, and the loss of sense of taste was lasted for three or four days and was returned to the normal state gradually, and by the 9th day after the operation the sense of taste was returned to the normal state. These results seem to be very important, even though there were not many cases tested, and significant in the relationship between the sense of taste of the anterior two-third side of the tongue and the chorda tympani lesions in the middle ear cavity of 3 the same side. We are still studying these tests to obtain more accurate and significant results with many cases to present the good report.