The current study is designed to clarify the neuroprotective effect of sevoflurane preconditioning on the patients underwent intracranial aneurysm surgery. The patients with cerebral aneurysm will be recruited in current study. The sevoflurane preconditioning will be performed before the surgical procedure. The neurological injury biomarkers, such as S-100b and NSE will be detected. The neurological function and recovery will be assessed after the surgery.