OBJECTIVE：To investigate the effects of dexmedetomidine on regional cerebral oxygen saturation and cerebral function in patients undergoing intracranial aneurysm embolization. METHODS ：Totally 44 patients undergoing intracranial aneurysm embolization in the First Affiliated Hospital of Hunan University of TCM during Jun. 2017-Aug. 2019 were collected and randomly divided into group D （22 cases）and group C （22 cases）. Ten minutes before anesthesia induction ，group D was given intravenous injection of Dexmedetomidine hydrochloride injection 1 μg/kg；group C was given buffered normal saline 20 μL. Both groups were induced with Propofol emulsion injection+Midazolam injection+Fentanyl citrate injection+Cisatracurium besylate for injection. During the operation ，group D was given Dexmedetomidine hydrochloride injection 0.5 μg（/ kg·h）+Fentanyl citrate injection+Benzsulfosum atracurium for injection+Propofol emulsion injection to maintain anesthesia ；group C was continuously pumped with buffered normal saline 0.5 μg（/ kg·h）+Fentanyl citrate injection + Benzsulfosum aratracurium for injection Propofol emulsion injection to maintain anesthesia. Before anesthesia induction （T0）， immediately after anesthesia。induction （T1）， 1 min after tracheal intubation （T2）， immediately after operation finished （T3），immediately afte extubation（T4），the mean arterial pressure（MAP），heart rate 中国药房 2021年第32卷第7期 China Pharmacy 2021Vol. 32 No. 7 ·865· （HR），regional cerebral oxygen satur ation（rSO2）were observed in 2 groups. The levels of neuron specific enolase （NSE）and S100 β protein in serum were measured at T1，T3，6 h after operation （T6）. The recovery time ，intraoperative blood loss ， nitroglycerin amount and the occurrence of ADR were recorded. RESULTS ：MAP and HR of group D at T 2-T4 were significantly lower than those at T 0；MAP and HR of group C at T 2-T4 were significantly higher than those at T 0；the group D were significantly lower than the group C at the same period （P＜0.05）；there was no statistical significance in rSO 2 between 2 groups at T 0-T4（P＞ 0.05）. The levels of serum NSE and S 100β protein in 2 groups at T 3 were significantly higher than at T 1；those in 2 groups at T 6 were significantly lower than at T 3，but those of group D were significantly lower than the group C at T 3（P＜0.05）；there was no statistical significance in the levels of serum NSE or S 100β protein between 2 groups at T 1（P＞0.05）. The recovery time of anesthesia，the amount of nitroglycerin ，the incidence of tachycardia ，nausea and vomiting ，restlessness，shivering and cough in group D were significantly shorter or lower than group C （P＜0.05）；there was no statistical significance in the intraoperative blood loss between 2 groups（P＞0.05）. CONCLUSIONS ：Dexmedetomidine can maintain the hemodynamic stability of patients with intracranial aneurysm embolization during the perioperative period ，has little effect on rSO 2 and brain function ，and has good safety.