Blunt chest contusion with rupture of bronchus is not common. Not all the patients will develop severe respiratory symptoms immediately after trauma until grannulation tissue appears in the later time. We had experienced one blunt chest contusion patient with left side main bronchus rupture without early respiratory symptom. The left side lung became collapse 7 days after trauma as the gannulation tissues appeared in the ruptured area gradually. After both ends of the ruptured bronchus were debrided and reanastomosed, the lung reexpanded again. Follow up for four years, she enjoyed her life as a normal person.