Abstract: Objective: To study the influence of kainate on the hippocampal neuron of rats and the expression of Bax/bcl-2.Methods: The rats were divided into two groups random ly.The ex perimental groupw as given intraperitoneal administration of kainate, and the control groupw as given phosphate-buffered saline solution (PBS).After 3 days, the loss of neuron in the hippocampus of rats was detected by Nissl staining.The neuronic apoptosis in the hippocampus was examined with terminal deoxy nucleotidyl-transferase mediated d-U TP-biotin nick end labeling (TUN EL);related gene Bax and Bcl-2 expression were marked by SABC method.Results: Kainate could induce neuron apoptosis and loss, up-regulation of bax and down-reg ulation of bcl-2 in the hippocampus of rats by intraperitoneal administration.Conclusions: The hippocampal neuron of rats can be impaired by intraperitoneal administration of kainate.Elevated expression of Bax/bcl-2 of neuron mig ht be involved in the pathophysiologic course of apoptosis in neurons.