To evaluate the protective effect of Ziziphi Jujubae Semen(ZJS) on 5-Fluorouracil(5-Fu) in cultured vestibular neurons(VN), neurotoxicity was assessed by XTT assay after VN was exposed to 3-24ug/ml 5-Fu for 48 hours. and also, the neuroprotective effect of ZJS was measured by XTT assay in these cultrures. Cell viability was remarkably decreased dose-dependently, after the treatment with 12ug/ml 5-Fu to cultured VN for 48 hours. In the neuroprotective effect of ZJS on the toxicity induced by 5-Fu, ZJS prevented the neurotoxicity induced by 5-Fu in these cultures. From above the results, it suggests that 5-Fu is toxic in cultured VN and herb extract, ZJS has protective effect over the neurotoxicity induced by 5-Fu.