Objective To find out the distinction between COPD accompanied by lung cancer and lung cancer alone. Methods This analysis was made on 86 cases COPD accompanied by lung cancer in our hospital in recent 5 years. Results We found that lung cancer is far more common in patients who have COPD than in those who have no COPD. The patients of COPD with the lung cancer have the characteristics of higher propotion in squamous cell carcinoma and could be discovered early. Conclusion Prevention and cure of chronic airway infection could prevent its change into cancer; The regular lung examination can find the early lung cancer.