Abstract： Objective To observe the effect of brain homogenate (BH) extracted from hypoxia-preconditioned mice on the viability and apoptosis of rat embryonic hippocampal neurons with hypoxia/reoxygenation-induced injury. Methods Rat embryonic hippocampal neurons primarily cultured for 8 days in 96 well tissue culture plate were divided into 5 groups, namely the normal control group (treated with PBS), H<,4>R<,48> group (with hypoxia for 4 h followed by reoxygenation for 48 h and PBS treatment), H0 group (with BH from normal mice prior to hypoxia/reoxygenation), H1 group (with BH from acute hypoxia-preconditioned mice and hypoxia/reoxygenation), and H4 group (with BH from hypoxia-preconditioned mice and hypoxia/reoxygenation). The viability and apoptosis of the cells in the 5 groups were observed by MTT assay and flow cytomertry, respectively. Results The cell viability was significantly higher in the normal control group than in H<,4>R<,48> group. In H0, H1, and H4 groups, the cell viability increased significantly as compared with that in H<,4>R<,48> group, and the cells in H4 group showed the highest viability. Apoptotie cells were scarcely observed in the normal control group, but were numerous in H<,4>R<,48> group. Compared with H<,4>R<,48> group, H0, H1, and H4 groups showed obviously reduced apoptotic cells, and the reduction was the most conspicuous in H4 group. Conclusion BH extracted from hypoxia-preconditioned mice may offer protection against hypoxic injury of rat embryonic hippocampal neurons challenged with hypoxia-reoxygenation by promoting the cell viability and decreasing cell apoptosis.