Abstract: The present investigation employed psychophysical and electrophysiological me-thods to study the compound action potential induced by square pulse stimulation onthe saphenous nerve. The first experiment was to establish an emotional scale of pain by observing the emotional states of nine subjects under various pain stimulation con-ditions. The second experiment applied electro-acupuncture on the same nerve andrecorded the changes of the sensory as well as the emotional components of pain dur-ing and after electro-acupuncture processes. The result indicated that electro-acupunc-ture had differential inhibitory effect on the sensory component and the emotionalcomponent of pain. This suggests: 1. Pain involves two related but different com-ponents (the sensory component and emotional component of pain); 2. Electro-acupuncture has stronger inhibitory effect on the emotional component of pain. Thisresult provides a new outlook for the improvement of clinical effect of acupunctureand for further study of pain mechanism.

Key words: NULL