The purpose of this study is to research the effects of acupuncturing BL40 and ST36 and to determine the mechanism of action of acupuncturing BL40 and ST36 by measuring the changes of regional cerebral blood flow (rCBF) and mean arterial blood pressure (MABP) in normal rats. To determine the mechanism of action of acupuncturing BL40 and ST36, pretreatment with indomethacine and methylene blue was performed. Acupuncturing BL40 and ST36 significantly increased rCBF, and the increased rCBF by acupuncturing BL40 and ST36 was significantly inhibited by pretreatment with indomethacin (1 mg/kg, i.p.), an inhibitor of cyclooxygenase, and methylene blue($10{mu}g/kg$, i.p.), an inhibitor of guanylate cyclase. Acupuncturing BL40 and ST36 decreased MABP, and decreased MABP by acupuncturing BL40 and ST36 was not changed by pretreatment with indomethacin and methylene blue. This result suggested that acupuncturing BL40 and ST36 might significantly increase rCBF by dilating arterial diameter and mechanism of acupuncturing BL40 and ST36 might be mediated by cyclooxygenase and guanylate cyclase.