Objective To investigate the risk factors of rupture of intracranial aneurysms.Methods Two hundred and seventy eight patients with cerebral aneurysms admitted from January 2000 to December 2013 were enrolled in study,including 122 cases with ruptured intracranial aneurysm (rupture group) and 156 cases without rupture (non-rupture group).The clinical data were collected from two groups,risk factors of aneurysm rupture were studied by univariate analysis and multivariate logistic regression analysis.Results The rates of female gender,smoking history,hypertension and atherosclerosis in rupture group were significantly higher than those in non-rupture group [70.5％ (86/122) vs.59.0％ (92/156),42.6％ (52/122) vs.29.5％ (46/156),63.9％ (78/122) vs.51.9％ (81/156) and 69.7％ (85/122) vs.51.3％ (80/156);x2 =3.943,5.175,4.034 and 4.319,respectively,all P ＜ 0.05];the width of aneurysm neck and diameter of aneurysm in rupture group were significantly lower than those in non-rupture group (all P ＜ 0.05).In addition,the rates of aneurysm rupture in patients with aneurysm diameter of ＜ 5 mm,5-8 mm and ＞8 mm were 63.4％ (64/101),40.9％ (38/93),25.0％ (20/84),respectively,Z =27.180,P =0.000;the rates of aneurysm rupture in patients with aneurysm neck width of ＜4 mm was higher than that with width ≥ 4 mm [67.3％ (66/98) vs.31.1％ (56/180),x2 =33.832,P =0.000].Multivariate logistic regression analysis showed that aneurysm diameter is an independent risk factor for rupture of intracranial aneurysm (OR =3.759,95CI:1.638-6.879,P =0.001).Conclusions The diameter of intracranial aneurysm in an independent risk factor for aneurysm rupture.Female gender,history of smoking,underlying hypertension and atherosclerosis,and the width of aneurysm neck may also related to the rupture of intracranial aneurysms.