To evaluate the e±cacy of microwave therapy via broncho¯berscope for treatment of severe trachea stenosis. Microwave tissue coagulation (MTC) and diathermy (MD) therapy via broncho¯berscope were performed on 37 patients with severe trachea stenosis diseases at least two times. The e®ective rate immediately after treatment was 100% in all cases. After one month, the rate remained 100% in the patients with benign diseases, but it dropped to 67% in the patients with malignant tumors. We have demonstrated that the microwave thermotherapy via broncho¯berscope is an e®ective method to treat patients with benign trachea stenosis noninvasively. For cancer patients with trachea soakage and blockage, it can be performed to improve their life quality by alleviating their agonies.