To compare the hemodynamic characteristics of posterior communicating artery aneurysm before and after embolization and investigate its relationship with aneurysm recurrence using a computational fluid dynamics simulation study. Thirteen patients undergone embolization of posterior communicating artery aneurysm between January 2008 and February 2010 were enrolled and divided into recurrent and recovered group according to their follow-up angiographic data. Aneurysm models were established using three-dimensional cerebral angiography data collected before and after embolization. Preoperative and postoperative hemodynamic modalities at aneurysm neck region were analyzed with computational fluid dynamics software using the finite element algorithm. In this study, computational models were set according to transcranial Doppler pulsatile flow, and the part of aneurysm occluded by spring coil is completely independent of the blood flow. In recurrent group, peak systolic wall shear stress and blood flow velocity at the aneurysm neck region were significant increased after the embolization. On the contrary, in recovered group peak systolic wall shear stress and blood flow velocity were significantly reduced after the embolization. The recurrent group also had higher post-embolization peak systolic wall shear stress and blood flow velocity than the recovered group. High wall shear stress and blood flow velocity after embolization at the neck region of posterior communicating artery aneurysm may promote early aneurysm recurrence.