Acupuncture anesthesia sometirnes fails to give sufficient analgesia which may be overcome by appropriate combination of non-narcotic analgetics. We measured 3-endorphin (β-EP) and cortisol contents in thyroidectomy under acupuncture analgesia (12 cases ) and acupuncture anesthesia combined with tetrahydropalrnatine (12 cases) by RIA- The results showed that the increase of β- EP and cortisol in the latter group was less than that of the former. tvhich proved that terahydropalmatine exerted a potentiating effect on acupuncture analgesia