This study was performed to compare the effects of epidural morphine and nalbuphine with general anesthesia for relief of pain after abdominal surgery. Patients were devided into three groups like Group I(General anesthesia), II(Epidural mor- phine) and III(Epidural nalbuphine). Pain score, gas passing and ambulation time were checked in all groups respectively. And side effects inclduing urinary retention and respiratory changes were evaluated too. The results were as follow. 1) The effects of epidural morphine and nalbuphine on pain relief were better than general anesthesia. And the effect of epidural morphine was superior to epidural nalbuphine too. 2) Ambulation time was the shortest in epidural morphine group. 3) Urinary retention, gas pasing time and respiratory changes were similar in a11 groups.