Recent studies have shown that narcotic drugs produce an intense prolonged analgesic action when injected into the subarachnoidal or extradural space of animals and man. In order to study the effects of intrathecal injection of morphine on postoperative pain relief and segmental block effect, we administered 0.25 mg of morphine sulfate (0.25 mg of morphine/1 ml normal saline) into lumbar subarachnoid space prior to brahial plexus block for upper extremity surgery group The results were as follows: 1) more than 20 hours analgesic effect at least 2) no segemental block effect in analgesia 3) some adverse effect (Nausea, Vomiting, Pruritus, Urinary retention).