Effects of opiate receptor blocker-naloxone ( 5mg/kg) on somatosensory evoked potentials ( SEP ) in 6 cats was studied. Other 6 cats were treated with normal saline as control. Results showed that the amplitudes of SEP were significantly elevated after 0.5h of aaloxone infusion. The changes of SEP-CCTp or CCTmn were no significant. It was suggested that large dosage of naloxone can favorably improve the electrical activites of neuron in the centre nerve system.