The incidence of traumatic rupture of the tracheobronchial tree has been increased considerably with advent of widespread mechanization and high speed era. Rupture of the bronchus is an unusual result of nonpenetrating trauma to chest. Early diagnosis and primary repair not only restore normal lung function but also avoid difficulties and complications associated with delayed diagnosis and repair. These complications are pneumonia, atelectasis and lung abscess secondary to the bronchial obtruction. We experienced a case of partial rupture on left main bronchus caused by nonpenetrating blunt chest trauma with rib fractures 1 year ago. He was suffered from progressively developing dyspnea on exercise and treated as bronchial asthma at other hospital. Bronchoscopic finding was the narrowed lumen of left main bronchus at 1cm from carina by web-like membrane. We confirmed by bronchogram and repaired by end to end anastomosis, which is rare delayed finding in bronchial rupture without pulmonary complications.