Abstract: Objective To observe the effect of huperzine A on cerebral cholinergic system in elderly patients during recovery from general anesthesia.Methods Thirty elderly patients undergoing elective surgery under general anesthesia were randomized in a double-blind manner into group I(n=15) to receive huperzine A(0.3 mg/2 ml) and group II(n=15) with normal saline(2 ml) given intravenously.Huperzine A or normal saline was administered 30 min before completion of the operation,and acetylcholine(Ach) concentration in the cerebral spinal fluid(CSF) of the patients was determined using high-performance liquid chromatography with electrochemical detector(HPLC-ECD) and the activity of cholinesterase inhibitors(ChE) evaluated with automatic biochemistry analyzer before general anesthesia induction(T1) and 5 h after operation completion(T2).Results In both the groups,Ach concentration in the CSF were lower at T2 than that at T1(P<0.01),and at T2,CSF Ach concentration was significantly higher in group I than in group II(P<0.01);in group I,the activity of CSF ChE at T2 was lower than that at T1(P<0.01),and also lower than at T2 in group II(P<0.01).Conclusion Huperzine A can inhibit cholinesterase to increase Ach,which has a positive effect on cerebral cholinergic system in elderly patients during recovery from general anesthesia.