Tonsillocoagulation was performed on 50 patients with chronic tonsillitis by virtue of YAG Laser. The patients' serum IgG, IgA, IgM, C3level and some acute phase reactant proteins (APRPs) including alpha 1-AGP, alpha 1-AT, Tf were measured pre- and postoperatively. In addition, tonsillar morphology was observed with light and electron microscope before and after tonsillocoagulation. Following up the patients for six to twelve months, we discovered that their immune function remained normal and that their symptoms of chronic tonsillitis had been controlled, it suggests that YAG Laser tonsillocoagulation can be a practical therapy for chronic tonsillitis.