Post - tonsillectomy pain is always aclinically severe problem. We took aramdomized study on 78 cases who received analgesiaafter tonsillectomy in recent five years. Some took nebulization dexamethasone (Dxm) and Gentamycin after surgery. The others receivednebulization of only Dxm. All these ways relieved the pain of post - tonsillectomy obviously, besides, they have not affected the growing of thepseudo- membrane in tosil fossia. Meanwhile we find the pain of post - tonsillectomy is not associated with the inflammation and can beeffectively eased by the hormone.