【Abstract】Objective: To develop mouse brain / pulmonary edema model under different conditions to calculate water content and make a comparative study. Methods: 50 male BALB / c mice were randomly divided into control and 4 experimental groups: 6000 m / 48 h, 6000 m / 72 h, 8000 m / 48 h, 8000 m / 72 h, 10 in each group. The precursor mass of each group of mice was recorded. Except for the blank group, the other groups were placed in the simulated plateau environment at the altitude of 6000m or 8000m, exposed for 48 h or 72 h, and the blank group was not treated. After the exposure time, the body mass was weighed, and the lung wet weight, brain wet weight, lung dry weight and brain stem weight were collected and calculated. Three different calculation methods were used to calculate the model water content and conduct differential analysis, and the pathological changes of brain and lung were observed by HE staining. Results :Except for the blank group, the body mass of mice in all experimental groups decreased significantly (P <0.01), and the body mass decreased most significantly after 72 h at the same altitude. Analysis of the pulmonary edema model: in the 6000 m / 48 h group, Not significantly different from the blank control group (P> 0.05), Pathological analysis showed slight pulmonary edema in the 6000 m / 48 h group; The calculation results of method 2 or method 3,6000 m / 72 h, 8000 m / 48 h, 8000 m / 72 h, Are significantly higher than the blank control group (P <0.01), Meanwhile, pathological analysis indicated significant edema in the lungs of these 3 groups, However, the lung water content of these three groups was not significantly different from the blank control group as calculated by method 1 (P> 0.05). Analysis of cerebral edema model: when calculated by method 1, the brain water content of each experimental group was significantly lower than that of the blank control group (P <0.01); the calculation results of method 2 and 3 were completely consistent, and the brain water content of each experimental group was significantly higher than that of the blank control group (P <0.01); the pathological analysis showed that the brain of the four experimental groups had significant edema. Conclusion: Method 1 has a more serious error. Methods 2 and 3 have similar calculation results, which both introduce the ability to correct body mass changes, and are recommended as the standard calculation method for the plateau brain / lung edema model.