It was found that in combined acupuncture-epidural anesthesia the clinicaleffect needling the Shu-points located the area of epidural blockage was not soeffective as that needling the extremity points located out of the block area.This might be result of the needling sensation originating from back having be-ing blocked partly after epidural blockage. This viewpoint was confirmed inthis study. In present study the effect of epidural blockage on cortical evokedpotentials in an animal model similar to the clinical condition was studied.