Objective: To anslysis the hemodynamic states of vertebrobasilar dolichoectasia based on computational fluid dynamics technique. Methods: The original DICOM format image data from a patient with vertebrobasilar dolichoectasia (VBD), were imported by the Mimics software directly,and the 3D Objects were constructed.The simulation of model was made with Ansys software, the hemodynamic parameters such as streamlines, wall shear stress(WSS) and wall pressure were described. Results: There was stable laminar flow in proximal basilar artery and was no blood flow mixed by bilateral vertebral artery.However, Spiral flows were appeared in distal tortuous basilar artery. The low WSS regions in the vertebrabasilar junction section and inferior segment of basilar artery were coincide with the high wall pressure regions.It could be speculated the initial growth regions might be located in the vertebrabasilar junction section and inferior segment of basilar artery.Local regions with low WSS and high wall pressure might be associated with the occurrence and development of VBD. Conclusion: CFD numerical simulation maybe can provide a theoretical basis for the role of hemodynamic factors in occurrence and development of VBD.