Abstract: Objective: To investigate the effect of target controlled infusion (TCI) with midazolam for shivering in patients undergoing epidural anesthesia.Methods: Forty patients undergoing lower-abdominal operation with shivering were randomly divided into two equal groups (n=20,respectively):group A combined TCI with midazolam,while group B combined intravenous injection with droperidol-fentany.The changes of vital sign were monitored before and during operation.The sedation degree was evaluated by the Observer's Assessment of Alertness/Sedation (OAA/S) Scale.The therapeutic effect of shivering was estimated.Results: The numbers of mean arterial pressure (MAP),heart rate (HR) and pulse oxygen saturation (SpO₂) were stable during the operation between two groups.They were within normal limits.Although the numbers of MAP and HR in group B after administration were lower than preoperative,the patients need not be treated.There were no significant differences in MAP and HR at different periods after the administration between two groups (P>0.05).While there was significant difference in SpO₂ at minite 10 (P<0.01).The effective power of treating shiver of group A was better than group B (P<0.01).There was significant difference in sedation scale at different periods after the administration between two groups (P<0.05 to P<0.01).The OAA/S scale in group A maintained 2 to 3.The scales were 3 to 4 in group B at minite 5 and 10.The sedation degree weakened along with time prolonged.Conclusions: TCI with midazolam for shivering in patients undergoing epidural anesthesia is safe and convenient and effective.