Abstract: In order to provide a theoretical basis for the clinical treatment of thoracic aortic aneurysms,a 3D finite element model of thoracic aortic aneurysm was constructed and a numerical simulation of hemodynamics was performed.Based on the clinical patient-specific CT data of thoracic aortic aneurysm and combined with digital image processing software MIMICS 11,an optimized surface model of thoracic aortic aneurysm was constructed.Then the surface model was imported into ANSYS ICEM CFD11.0 to generate volume mesh.At last CFD analysis was performed using ANSYS CFX11.0.A finite element model suitable for hemodynamics analysis of patient-specific thoracic aortic aneurysm was established.Distribution and changes of streamlines,velocity vector,pressure and wall shear stress were obtained in the patient-specific model.The model with digital and patient-specific feature can be applied to hemodynamic analysis of thoracic aortic aneurysm and rupture mechanism of thoracic aortic aneurysms in patient can be analyzed based on the model.