Objective To evaluate the effectiveness of simvastatin for patients with aneurysmal subaraehnoid hemorrhage.Methods Systematic literature retrieval was carried out to obtain randomized controlled trials of simvastatin in patients with aneurysrnal subarachnoid hemorrhage before October 2015.Methodological quality assessment and data collection were performed by two individual reviewers.A Meta-analysis was performed by RevMan 5.1 software.Results Five studies,a total of 951 patients,were included.Meta-analysis showed that simvastatin could not reduce cerebral vasospasm (RR=l.26,95％ confidence interval [95％CI]:0.9-1.75,P=0.170),delayed cerebral ischemia (RR=1.06,95％CI:0.88-1.26,P=0.000),poor outcome (RR=1.05,95％CI:0.90-1.23,P=0.540),or mortality (RR=0.95,95％CI:0.62-1.44,P=0.800).Conclusion Simvastatin could not prevent cerebral vasospasm and delayed cerebral ischemia after aneurysmal subarachnoid hemorrhage,and could not improve the prognosis.