Zizypus is one of the herbs widely used in Korea and China due to CNS calming effect. The present study aims to investigate the effect of the methanol extract of Zizyphi Jujube Semen (ZJS) on kainic acid (KA)-induced neurotoxicity in cultured rat cerebellar granule neuron. ZJS, over a concentration range of 0.05 to $5;{mu]g/ml$, inhibited KA $(500;{mu}M)-induced$ neuronal cell death, which was measured by a trypan blue exclusion test and a 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl-tetrazolium bromide (MTT) assay. Pretreatment of ZJS $(0.5;{mu}g/ml)$ inhibited KA$(50;{mu}M)$-induced elevation of cytosolic calcium concentration $([Ca^{2+}]_c)$, which was measured by a fluorescent dye, Fura 2-AM, and generation of reactive oxygen species (ROS). ZJS $(0.5;{mu}g/ml)$ inhibited glutamate release into medium induced by KA $(500;{mu}M)$, which was measured by HPLC. These results suggest that ZJS prevents KA-induced neuronal cell damage in vitro.