Abstract: Objective To explore the imaging features of chest radiography and CT in patients with avian influenza A (H7N9).Methods The imaging data of chest radiography and CT in 4 patients with H7N9 confirmed by real-time RT-PCR assay were retrospectively analyzed.All patients had chest radiography at first and 3 underwent CT examination,3 had follow-up radiography.Results Chest radiographs showed increased lung markings with pulmonary consolidation and interstitial change in 4 cases and consolidations were bilaterally distributed in 3 cases.The imaging appearances changed quickly during the follow-up.The bilateral consolidations,multiple ground-glass opacities,pleural effusion,hilar and mediastinal lymphadenopathy were found on CT.Conclusions Avian influenza A (H7N9) has certain imaging features on chest radiography and CT,which is sinilar to those of H1N1 influenza.The final diagnosis of the avian influenza A (H7N9) depends on epidemiology and laboratory test.