Objective To reproduce a rat model of acute mountain sickness by using a hypobaric chamber to simulate the plateau environment, and to study the related physiological parameters. Methods A total of 70 male Wistar rats were randomly divided into normal control (NC) group, and 6 hypobaric hypoxia groups (10 each) in which rats were housed in a hypobaric chamber and exposed to the enviroment simulating high altitude of 5000m and 6000m for 12h, 24h and 48h respectively. Memory Morris water maze test was conducted to evaluate the changes in working memory of rats in space. Histological changes in lung and brain tissue were observed. Blood from abdominal aorta was collected to analyze the parameters of blood gas. The histopathological changes in lung and cerebrum were observed, and their wet/dry ratios were calculated. Results Reduction in activity or even death was found in hypobaric hypoxia groups, and arterial PaO2 was significantly decreased in all rats of hypobaric hypoxia groups. Compared with NC group, rats exposed to a simulated altitude of 5000m for longer than 24h and 6000m for longer than 12h exhibited longer latency period in finding the hidden platform, shorter expedition time for target quadrant, and less frequency of platform crossing in the Morris water maze test (P<0.05). After exposure to simulated altitudes of both 5000m and 6000m for 48h, pathological changes were observed in lung and cerebrum, and wet/dry ratio of lung and brain was significantly increased compared with that of NC group. Conclusion Indexes of rat model of acute mountain sickness by using a hypobaric chamber show different changes at respective time points. Therefore the changes in multiple physiological indexes of mountain sickness can be assessed by using this animal model.\n\t\t\n\t\tDOI: 10.11855/j.issn.0577-7402.2015.09.06