Objective : Experimental studies have been done to elucidate the effect of kangwhalyupung-tang(KWYPT) on neuronal cell damage induced by brain ischemia. Method : The cytotoxic effect of ischemia was measured in the MTS assay cultures. MTS assay, INT assay, neurofilament(NF) enzymeimmuno assay(EIA). And the KWYPT on ischemia-induced neurotoxicity were examined by in vitro assays. Results : 1. The KWYPT protected effectively neuronal cell-death resulted from brain ischemia induced by the treatment of $95%N_2/5%CO_2$ for 10 min in those dependent fashion. 2. The KWYPT effectively increased the amount of NF resulting from brain ischemia, induced by the treatment of $95%N_2/5%CO_2$ for 15 min in those dependent fashions. Conclusions : KWYPT protects the brain ischemia-induced neurotoxicity through the increase of cell viability and of neurofilament in dose-dependent manner.