Aorta provides as the passageway for blood in supplying nutrients to human body is the vital organ for human. Whenever, aorta has pathologic change might be life threatening emergency due to massive blood loss. The most common encountering conditions are aortic aneurysm rupture and acute aortic dissection and the most lesions sites are located near the aortic arch. The etiology for these pathologic changes is closely related to the intra-aortic high-speed, high-pressure pulsatile blood flow. Study the blood flow and the hemodynamic change might help us to understand the pathologic change and further prevent its happening. Therefore, we tried to use the computational fluid dynamics methodology to understand the flow dynamics in the aorta crossing the aortic arch. The axial velocity profiles and secondary flow vectors were plotted at two time points during systolic phase. The primary axial flow velocity skewed from medial side of aorta to lateral side after pass through aortic arch and the secondary flow developed as counter-rotating vortices in the middle plane.