【Abstract】 Objective To analyze the lung pathological features of type A H1N1 influenza and respiratory failure. Methods The data of imaging and aspiration lung biopsy of five patients with type A H1N1 influenza and respiratory filure since October 2009 were retrospectively analyzed. Results Common clinical manifestations of patients with type A H1N1 influenza and respiratory failure were rapid progress of illness after common cold-like symptoms with high fever, dyspnea, severe hypoxemia, large amounts of bloody sputum, wet rales over both lungs, and with other organs involved or even septic shock. Early lung pathological features were inflammatory exudate in alveoli and lung interstitium, infiltration of inflammatory cells, and extensive hemorrhage. Middle and late pathological features were hyperplasia of alveolar epithelial,disconnection of alveolar septa, replaced of alveolar spaces by fibrosis. Conclusions The pathology of patients with type A H1N1 influenza and respiratory failure is similiar with ARDS. Development of treatment strategies targeted to pathological characteristics of ARDS caused by type A H1N1 influenza is of greatsignificance for effective and timely treatment.