Background: Epidural analgesia has been widely used for postoperative pain relief. However, it is not known which regimen provides the best result due to many variety. The aim of this study is to evaluate the analgesia and side effects of epidural mixute of fentanyl, bupivacaine and clonidine, as one kind of regimen. Methods: One hundred adult patients scheduled for upper abdominal surgery under general anesthesia were evaluated. Epidural catheterization was done after operation. A bolus, 0.1% bupivacaine 10 ml containing fentanlyl 100 ${mu}g$, was administered and followed up with continuous infusion of mixture of fntanyl 600 ${mu}g$, 0.5% bupivacaine 20ml and clonidine 150 ${mu}g$ at a rate of 2ml/hr for 50 hours. Analgesia was assessed using VAS, PHS and PRS. Side effects and number of patients who took additional analgesics were evalutated. Plasma samples were obtained to determine fentanyl concentration. Results: After the administrations of drugs, patients pain scores decreased notably, and pain relief scores increased significantly. Minimum side effects were noted. Twenty-one patients required additional analgesics. Plasma concentration of fentanyl was 0.07~0.14 ng/ml. Conclusion: Epidural infusion of mixture of fentanyl, bupivacaine and clonidine is an effective regimen for postoperative pain relief after upper abdominal surgery.