Objective To discuss the HRCT imaging Feature of Influenza A H1N1 Complicated with Severe lung injury. Methods The 65 patients conventional CT and HRCT imagine of Influenza A H1N1 Complicated with Severe lung injury were retrospectively analyzed. Results ⑴ Lung parenchyma imaging feature: the 20 imaging of uniformity lung consolidation, compared with inflatable bronchus and gland alveolus nodules; the 36 patching and blurred imaging, half or bilateral lungs distribution and always in middle and lower lung; the 44 consolidation imaging in subpleuralis, patching or spherical exudative process compared with uniformity density and edge unsharpness; the 43 imaging ground-glass opacity shadows, large or patching distribution, grid or nodosity changing, 21 in lung parenchyma and 22 in subpleuralis. ⑵ lung mesenchyma imaging feature: the 35 imaging of thickening and derangement lung marking ; the 23 imaging of thickening interlobular septum; the 24 imaging of aristiform or nodosity shadows; the 32 imaging of grid shadows. Conclusion The HRCT imaging not only objectively evaluate Influenza A H1N1 Complicated with Severe lung injury, but also guide and assess the clinical efficacy.