Cheonghunhwadam-tang have been used in oriental medicine for many centuries as a therapeutic agent of vertigo by wind, fire and phlegm. CHT Gamypang(CTG) was CHT adding Aurantii Fructus(AF). The effects of CTG on the regional cerebral blood f1ow(rCBF) and mean arterial blood pressure(MABP) is not known. The mechanical Study of CTG on the cerebral hemodynamics is not known too. Therefore, purpose of this Study was to investigate effects of CTG on the rCBF and MABP, mechanism of CTG on the cerebral hemodynamics in rats. The changes of rCBF and BP was determinated by Laser-Doppler Flowmetry(LDF). The results were as follows ; CTG extract was significantly decreased rCBF in a dose-dependent, but the change of MABP was not shown. Pretreatment with propranolol(3mg/kg, i.v.) was significantly increased CTG(10 mg/kg, i.v.) induced decrease of rCBF. Pretreatment with indomethacin(3mg/kg, i.v.) and methylene blue(10㎍/kg, i.v.) were increased CTG induced decrease of rCBF too. This results suggest that the mechanism of CTG is mediated by adrenergic β - receptor, guanylate cyclase and cyclooxygenase.