Background: As patients are positioned at insulated bed and practitioner are positioned at insulated floor or shoes, it could be a cause of lessening effect in acupuncture practice. We investigated how Ground connection could influence on the electrical meridian potential between practitioner and patient during acupuncture practice. Method: We treated 30 normal healthy subjects with acupuncture and measured changes in the electrical potential between the stomach meridian points ST-39 and ST-37 in response to light touch after insertion of a needle at ST-36. At first, we stimulated needle and measured electrical potentials for non ground, patient ground only, practitioner ground only, all ground, respectively. Result: All ground subject elicited positive mean potential $44.6{pm}19.2{mu}V$ and showed $181.4{pm}59.7{mu}V$ peak to peak potential. practitioner ground only showed negative mean potential $-51.5{pm}9.3{mu}V;and;367.4{pm}27.8{mu}V$ of peak to peak potential. Patient ground only revealed no mean potential as $2.9{pm}1.3{mu}V,;16.4{pm}11.9{mu}V$ of peak to peak potential. All ground showed no mean potential as $1.6{pm}0.7{mu}V,;3.3{pm}1.9{mu}V$ of peak to peak potential. respectively.