【Abstract】 Objective To summarize the clinical data and find the characteristics of the first 6 severe cases of human infections with avian influenza A (H7N9) in Sichuan Province，so as to help the prevention and control of epidemic situation with avian influenza and improve the level of diagnosis and treatment of the disease. Methods Clinical data were collected and analyzed retrospectively from 6 patients with confirmed human infections with avian influenza A (H7N9).Results The symptoms in common of the 6 cases were high fever, cough and dyspnea. A contact history with living poultry and a long time treatment outside the hospital were found. Thus antiviral drugs were taken more than 48 hours after onset. During hospitalization, a comprehensive treatment was received by all the cases, such as mechanical ventilation, antivirus, anti infection. All of them turned negative with viral nucleic acid after treatment (two consecutive testing), of which one case was discharged with rehabilitation, three cases died, and the other two cases were still in the hospital. Conclusion Early screening for key population， early diagnosis and treatment are the key points to reduce the mortality of human infections with avian influenza A (H7N9).