This study investigated the comparison of electromyographic change of neuromuscular blocking effect induced vecuronium between the ulnar, facial and tibial nerve in 24 healthy adult patients anesthetized with thiopental, N2O and enflurane. Neuromuscular monitoring commenced immediately after administration of thiopental. After supramaximal stimulation was achieved, a bolus of vecuronlum 0.08mg/kg was injected intravenously. And then single twitch nerve stimulation(T1) was applied to the nerves using surface electrodes and the electrical response of muscles recorded using the RELAXOGRAPH(Dates Co.). The patients were allocated randomly to 3 groups of 8 patients respectively: the ulnar nerve troup was the control, and the facial nerve group and the tibial nerve group were the studing group. We assessed electromyographic responses from abductor digiti minimi muscle in the ulnar nerve, orbicularis oris muscle in the facial nerve and flexor hallucis brevis muscle in the tibial nerve to single twitch nerve stimulation respectively. And the onset time, the time from injection of vecuronium to 25% and 75% recovery to T1, and recovery index of the ulnar, facial and tibial nerve groups were measured. The obtained results were as follos: 1) The onset time was faster in the facial nerve group compared with the ulnar nerve group. 2) The time from injection of vecuronium to 25% recovery of T1 was more prolonged in the facial nerve group compared with the ulnar nerve group. 3) The time from injection of vecuronium to 75% recovery of T1 and recovery index were more shorter in the tibial nerve group compared with ulnar nerve group.