Abstract: Objective: To evaluate the influence of propoflo-low dose ketamine in sacral anesthesia in infants on circula,respiratory and bispectral index(BIS).Methods: Thirty infants were randomly divided into two groups(15 cases in each):group A were injected propofol 1.5 mg/kg and maintenanced by continuous propofol 1 mg·kg^-1·h^-1 infusion;group B were injected propofol 1.5 mg/kg,sedation was maintenanced by continuous propofol 1 mg·kg^-1·h^-1 and ketamine 0.5 mg·kg^-1·h^-1 infusion.Sacral anaesthesia was given five minutes after injecting propofol.Rating of propofol infusion was adjusted to BIS in the operation.Results: In group A,HR and MAP during operation were much lower than those before operation(P<0.01).BIS of emergence in group A was lower than that in group B(P<0.05),The emergence time and the dose of propofol during maintenance in group A were much higher than those in group B(P<0.01).Conclusions: Propofol-low dose ketamine has the advantages of hemodynamic stability,lower dose of propofol and rapider emergence as compared with using propofol alone in sacral anaesthesia in infants.