Abstract： Objective To explore the chest features of patients with the novel influenza type A H1N1 on HRCT. Methods One hundred and seventy-two chest HRCT examinations on 163 cases with Influenza type A H1N1 (9 cases were reexamed) were retrospectively analyzed using standard pulmonary window and mediastinal window, respectively. HRCT imaging appearances were summarized. Results Ninety-seven cases showed normal on chest HRCT, while the others showed abnormalities of parenchymal and interstitial. Among them, HRCT identified ground-glass opacity in 35 cases (53.0%), centrilobular nodules in 30 cases (45.5%), thickening of intralobular septa in 31 cases (47.0%), intralobular thin reticulation and micro-nodule in 8 cases (12.1%), single-lobular inflammation in 19 cases (28.8%), consolidation of lung(the large consolidation and multiple small consolidations)in 15 cases (22.7%), pulmonary atelectasis in 3 cases (4.5%), and irregular lines in 2 cases (3.0%). Pleurisy was also revealed including 8 cases with right pleurisy, 5 cases with left pleurisy, and 19 cases with bilateral pleurisy. Mediastinal and axillary lymphadenopathy were found in 7 cases, who were spared of pleural effusion. All above abnormalities resolved quickly after anti- virus treatment. Conclusion Parenchymal and interstitial abnormalities, mediastinum and axillary fossa lymphadenopathy, and pleural effusion were the common findings on HRCT in patients with Influenza type A H1N1, which were similar to those of other viral pneumonia.