In recent 5 years, 33 cases of tracheobronchial benign lesions have been treated with the method of Nd-YAG laser via bronchoscope. The follow-up survey has shown that the curative ratio reached 66.7 percent and total effective rate came up to 78.8 percent. There was significant relationship between the therapeutic effectiveness and types of lesions (P < 0.01). It had higher cure rate in benign tumour, tuberculous granuloma and foreign body's granuloma than that of inflammatory granuloma and amyloidosis. This method is a new and effective one for treating benign pathologic changes in air passage. The indication and prevention of complications have been discussed.