To evaluate the effect of Baepungtang(BPT) water extract on cultured mouse spinal sensory neuron which was inhibited by xanthine oxidase(XO) and hypoxanthine(HX)-induced oxigen radicals, MTT assay, NR assay, Neurofilament enzymeimmuno assay and LDH activity assay were carried out after the cultured mouse spinal sensory neuron were preincubated with various concentrations of BPT water extract for 3 hours prior to exposure of XO/HX. The results obtained were as follows: 1. XO/HX, a oxigen radical, decreased the survival rate of the cultured mouse spinal sensory neuron cell on NR assay and MTT assay. 2. $MTT_{50}$ value and $NR_{50}$ value of XO/HX were 30 mU/ml XO/O.2 mM HX. 3. BPT water extract have efficacy of increasing neurofilament. 4. BPT water extract have efficacy of increasing LDH activity. From above the results, It is concluded that BPT has marked efficacy as a treatment for the damages caused in the XO/HX-mediated oxidative process.