Cheonghunhwadam-tang(CHT) have been used in oriental medicine for many centuries as a therapeutic agent of vertigo by wind, fire and phlegm. CHTGR was CHT adding Gastrodae Rhizoma. The effects of CHTGR on the regional cerebral blood flow(rCBF) and mean arterial blood pressure(MABP) is not known. A comparative Study of action-mechanism of CHT and CHTGR on the cerebral hemodynamics is not known too. Therefore, purpose of this Study was to investigate effects of CHT and CHTGR on the rCBF and MABP, compare action-mechanism of CHT and CHTGR on the rCBF and MABP. The changes of rCBF and BP was determinated by Laser-Doppler Flowmetry(LDF). The results were as follows ; CHT extract was increased rCBF in a dose-dependent, but was not changed MABP compared with CHT non-treated group. CHTGR extract was decreased rCBF and MABP compared with CHTGR non-treated group in a dose-dependent. Action of CHT is not related with adrenergic β-receptor, cyclooxygenase and guanylate cyclase, but action of CHTGR is related with guanylate cyclase.