Background : The location of acupoints on rat, which may differ from that of human body due to anatomical structure, is defined variously among researchers, which may cause the problem of low repeatability and objectivity. Design : The measurement of hind limb consist of measuring the distance between knee joint and tibia tubercle in order to set the knee joint as common criteria. Based on it, the three mostly referred location of ST36 were represented with the knee joint as a datum point and compared. The electroacupuncture stimulation was administrated after the abdominal pain was induced by acetic acid. And the analgesic activity of each ST36 acupoint was evaluated by measuring the number of writhing reflex, in order to observe the differences of treatment effect in accordance with the location of ST36 acupoints. Results : The result of measurement confirmed the differences in the acupoint location of ST36 among researchers. The writhing reflex test using the acetic acid-induced abdominal pain stimulated with electroacupuncture of 100Hz showed that there were statistically significant differences in the analgesic effect between control group and three ST36 groups (P<0.05). However there were no differences observed among three mostly referred location of ST36 acupoints (P>0.05). Conclusions : We recommend "the point located 6.5 mm below the knee joint at the anterior tibial muscle" as a standard ST36 acupoint location qualified by the WHO Standard Acupuncture Point Locations in 2008.