Objective To investigate the clinical application value of microendoscope in the treatment of laryngeal,tracheal,and bronchial diseases.Methods Under microendoscope,laryngological operations or tracheal or bronchial foreign body removal were carried out in 166 cases,including 19 cases of vocal nodule,75 cases of polyp of the vocal cord,16 cases of papilloma of the vocal cord,6 cases of cyst of the vocal cord,9 cases of cyst of the epiglottis,5 cases of laryngeal hemangioma,19 cases of laryngeal amyloidosis,3 cases of keratosis of the vocal cord,2 cases of leukoplakia of the vocal cord,6 cases of glottic cancer,and 6 cases of tracheal or bronchial foreign body.Results Foreign bodies in the trachea or the bronchus were removed successfully in all the 6 cases.Of the rest of 160 cases,laryngological operations were accomplished smoothly in 157 cases while a relatively large amount of hemorrhage was encountered in 3 cases and treated with microwave hemostasis.The operation time was 30~60 min(mean,45 min).No postoperative complications occurred.Follow-up observations for 2~12 months(mean,6 months) showed 148 cases of full recovery of vocal function and 12 cases of improvement.No recurrence was found in the 6 cases of glottic cancer during 1 year of(follow-up).Conclusions The application of microendoscope in the treatment of laryngeal,tracheal,and bronchial diseases has advantages of broad surgical view and direct and clear visualization.This minimally invasive procedure can remove the lesion thoroughly and reserve functions to the greatest advantages.