Objective To use numerical simulation technology for analyzing the hemodynamic and morphological factors for rupture status of posterior communicating artery aneurysms. Methods A total of 39 posterior communicating artery aneurysms treated in Changhai Hospital were recruited in the present study during January to December 2011, and they included 28 ruptured and 11 unruptured ones. The 3-dimensional model of the aneurysms were constructed, and the digital subtraction angiography data were obtained. Then the hemodynamic analysis of the aneurysms was done using the method of computational fluid dynamics. Results The aspect ratio (AR) was 1.233±0.483 in the ruptured group, which was significantly higher than that in unruptured group (0.832±0.252, P=0.002). The normalized mean wall shear stress (WSS) was significantly lower in ruptured group than in unruptured group (0.545±0.259 vs 0.761±0.216, P=0 .015). And the percentage of the low WSS area (LSA) in ruptured group was significantly higher than that in unruptured group (\[11.669±16.041\]% vs \[1.236±2.212\]%, P=0.040). Other parameters, including size ratio (SR) and oscillatory shear index (OSI), showed no significant differences, between the two groups. Conclusion Higher AR, lower WSS and higher LSA may be risk factors for aneurysmal rupture.