The purpose of this study is to examine the toxic effects caused by glucose oxidase (GO) and the effects of Hyungbangjihwangtang (HJT) water extracts on the treatment of the toxic effects. For this purpose, experiments with the cultured hippocampal cells from new born mice were done. The results of these experiments were as follows. 1. GO decreased the survival rate of the cultured cells on MTT assay and NR assay. 2. HJT has the efficacy of decreasing the lipid peroxidation. 3. HJT has the efficacy of increasing the amount of neurofilaments. 4. HJT has the efficacy of decreasing the activation of protein kinase C(PKC). From the above results, it is concluded that HJT has marked efficacy as a treatment for the damages caused by the GO-mediated oxidative stress. Further clinical study of this pharmacological effects of H]T should be completed.