On twenty patients and ten healthy adult volunteers, pain threshold was measured by a dolorimeter (Pain meter NYT-5) to clarify whether analgesic effects of electrical acupuncture on various body surface may be changed by acupuncture points or not.<br>Electrical acupuncture was performed to the traditional acupuncture points on the two meridians. A group is the combination of LI 10 (Shousanli) and LI 14 (Hoku) on the right side, the other is the combination of ST 36 (Tsusanli) and ST 40 (Liangchiu) on the right side.<br>Measured points of pain threshold are (1) face, (the point 2cm above from the center of both eyelids), (2) (3) left and right upper extremities (LI 11; Chuchih) and (4) (5) left and right lower extremities (ST 41; Chiehhsi).<br>In the Shousanli-Hoku group, pain thresholds of face, both upper extrimities increased significantly. However, those of both lower extremities were not significantly changed.<br>In the Tsusanli-Liangchiu group, pain thresholds of the upper and lower extremities on both sides increased significantly. However there were no significant changes in the forehead.<br>In comparison of two groups, increases of pain thresholds of both lower extremities were observed in significantly more cases with acupuncture to Tsusanli and Liangchiu points than those with Shousanli and Hoku points by the Chi-square test (p<0.01). From this fact, acupuncture of Tsusanli-Liangchiu points seems to be more effective on the lower extremities than that of the Shousanli-Hoku points.<br>Therefore, we conclude that effects on pain threshold by electrical acupuncture depend on various points on meridians and are not evenly shown on the whole body surface.