Objective        To determine the relationship between the morphological features and rupture risk of intracerebral aneurysm.       Methods        An retrospective analysis was carried out on the clinical data of 194 intracranial aneurysms in 154 patients (61 with 82 ruptured aneurysms and 93 with 112 ruptured) who diagnosed in our hospital from December 2009 to June 2011. Their three-dimensional geometries were evaluated for a range of morphological parameters. The parameters included depth

neck width

aspect ratio (AR)

with daughter sac or not

and number and position of daughter sac.       Results        The mean depth

mean neck width and mean AR were 4.95±4.80 mm

3.55±3.10 mm

1.21±0.68 respectively for the patients with ruptured aneurysms

and 2.75±2.65 mm

2.85±1.90 mm

and 0.96±0.55 respectively for those with unruptured aneurysms. Significant difference was found in the aneurysms with daughter sac or not between the ruptured and unruptured groups （P＜0.05）. The critical values of depth

neck width and AR in intracranial aneurysms for rupture risk were 3.65 mm

3.35 mm and 1.135 respectively. The aneurysms with depth over 3.65 mm had the risk of rupture by 3.76 times higher than those with lesser depth. The aneurysms with neck width less than 3.35 mm had the risk by 2.05 times higher than those with width larger. When AR was over 1.135

the risk of rupture was increased by 3.18 times. The aneurysms with daughter sac had the risk of 5.64 times higher than those without.       Conclusion        The depth

neck width and AR of intracerebral aneurysm are risk factors for aneurysm rupture. Longer depth

narrow neck width

larger AR and having daughter sac contribute to the risk of rupture.