In this paper effect of EA on nociceptive responses after topical application of bicuculline on the cortical somatosensory area of rats was investigated.Changqiang and Yaoshu point were selected for electroacupuncture. The results showed that the effect of EA on tail flick latency elecited by radiant heat and vocalization threshold elicited by electrical stimulation of tails in rats were increased after topical application of bicuculline on the cortical somatosensory area bilaterally;whereas there were no statistically changes in tail flick latency and vocalization thaeshold when the drug was applied unilateraly.It suggests that the cerebral cortex is involved in the modulation of nociceptive responses at the level of the brain stem and the spinal cord.