Most acupuncture points correspond to low skin-resistance points (LSRP) on the body surface along the meridians. We did three experiments which conformed that the skin nitric oxide (NO) concentration and expression of neuronal nitric oxide synthesis (nNOS) were higher than those in non-acupoints, and non-meridian control points. Noradrenaline (NE) synthesis/release was modulated by exogenous NO donor and selective inhibitor of nNOS in the skin acupoints/meridians. Skin electrical currents in low skin resistance points were modified by L-arginine-derived NO synthesis and NE. As a conclusion, NO-NE contribute to low resistance characteristics of acupoints and meridians.