This study was designed to investigate the effects of Mokhyangjoki-san extract (MJS) on the improvement in cerebral blood flow (rCBF) in cerebral ischemic rats, and further to determine cytokines production (IL-1β, TNF-α, IL-10, TGF-β) of MJS. The results in cerebral ischemic rats were as follows ; The rCBF was significantly and stably increased by MJS (10 ㎎/㎏, i.p.) during the period of cerebral reperfusion, which contrasted with the findings of rapid and marked increase in control group. In cytokine production in serum from femoral arterial blood 1 hr after middle cerebral arterial occlusion, MJS significantly decreased IL-1β and TNF-α production, and increased IL-10 production compared with control group. In cytokine production in serum from femoral arterial blood 1 hr after reperfusion, MJS significantly decreased IL-1β and TNF-α production compared with control group. IL-10 and TGF-β1 production in MJS group were significantly increased compared with control group. These results suggested that MJS significantly and stably increased rCBF by inhibiting the production IL-1β and TNF-α, and accelerating that of IL-10 and TGF-β. The result in nerve cells was as follows ; MJS significantly inhibited lactate dehydrogenase activity in vitro in a dose-dependent manner. This result suggested that MJS prevented the neuronal death.