This work is to study whut the analgesia of EA is related with specificity of channel point or innervation of point. The discharges of 28 NRM neurons and their nociceptive responses induced by stimulation of dental pulp or tail tip in rats were recorded. The effects of EA of "Shangguan" and "Yanglingquan" of gall bladder channel of foot shaoyang on NRM neurons and their nociceptive responses were compared. and with that of "Xiaguan" and "Zusanli" of the stomach channel of foot Yangming. "Shangguan" and "Xiaguan" were located in the depressions at the upper and lower border of zygomatic arch respectively, and innervated by the n. trigeminus. The hind leg points "Yanglingquan" is located in the depression anterior and inferior to capitulum fibulae above "Zusanli" and both were innervated by n. peroneus communis. The results showed that EA of "Shangguan" or "Xiaguan" could activate NRM, increasing unit discharges about 70-120% for 10-15 minutes (P < 0.05-0.001) and inhibit both nociceptive responses, but the inhibition on the nociceptive response induced by dental pulp (about -60% for 5-10 minutes, P < 0.05-0.001) was stronger than that by tail tip (no effect or about -30% occasionally). "Yanglingquan" or "Zusanli" EA could also activate NRM and inhibit the nociceptive responses, but the inhibition on the nociceptive response of tail stimulation about -60-(-)40% for 30 minutes, P < 0.05-0.001) was stronger and longer than that of dental pulp (about -40% for 5-10 minutes, P < 0.05-0.001).(ABSTRACT TRUNCATED AT 250 WORDS)