Abstract: Objective To establish a hypoxia ammial model with differen texposed periods and severe intermittent hypoxia and to explore effects of severe interm ittent hypoxia on learning and memory function inrats.Methods Male Wistar rats(n=48) were randomly divided intochronic intermitten thypoxia group and control group.The 5% hypo xia models was made with hypoxia box.AT2, 4, 6, and 8 weeks after hypoxia, the morphologic changes of neuron were observed with HE staining.The learning and memory ability of the rats were assessed with Morris water maze.Results Compared with the control group, neuronal morphologic structure in the hypoxia group was damaged significantly.The survival neuronal density was decreased with prolonged hypo xia(13.18±2.18).The mean of escaping latency period was 49.17±8.87, 58.47±6.98, 65.15±7.44, and 68.42±7.91 seconds at 2, 4, 6, and 8 weeks in intermittent hypoxia group,which was decreased with prolonged hypoxia(P < 0.5).Conclusion Intermitten thypoxia can cause nervecell damage and learning memory dysfunction.The damage increases with the prolonged in termittent hypoxia.