Abstract: Objective To explore the risk factors and survival prognosis of aneurysmal subarachnoid hemorrhage (SAH) complicated with cerebral edema. 
Methods A total of 315 patients with aneurysmal SAH were enrolled as the research subjects, and they were divided into cerebral edema group (n=78) and non-cerebral edema group (n=237) according to occurrence of cerebral edema. Logistic regression analysis was used to analyze risk factors for cerebral edema in patients with aneurysmal SAH. The patients were divided into favourable prognosis group (n=42) and poor prognosis group (n=36) according to modified Rankin scale (mRS) score, and the factors affecting the poor prognosis of patients was analyzed by logistic regression analysis. 
Results Age ≥ 60 years and intracranial infection were independent risk factors for cerebral edema in patients with aneurysmal SAH (P＜0.05). After 1-year follow-up, 36 patients had poor prognosis. Age, Hunt Hess grade, CT Fisher grade, and number of lesions were independent influencing factors for poor prognosis in patients with aneurysmal SAH complicated with cerebral edema (P＜0.05). 
Conclusion Aneurysmal SAH patients with advanced age and intracranial infection should pay close attention to the occurrence of cerebral edema. For elderly patients with Hunt-Hess grade Ⅲ-Ⅳ, CT Fisher grade 4, and multiple lesions, clinicians should pay attention to the prognosis of patients and prevent the occurrence of poor prognosis. 

Key words: subarachnoid hemorrhage, cerebral edema, risk factors