Abstract: In the present study, the effects of different altitudes environment simulated in hypobaric cabin on morphological structure of lung tissues in male Kunming mice was assessed using microstructure and ultrastructure of lung tissues and selected blood oxygen values. The results showed that the mice in the simulated hypobaric hypoxia environment had significantly higher thickness of alveolar septum, arithmetic mean thickness of the lung air-blood barrier, arteriovenous oxygen difference, and arterial and venous blood oxygen saturation difference (p<0.05). The morphological structure changes of the lung tissues in mice was caused by the hypobaric hypoxia environment, providing the adaptability to the hypobaric hypoxia environment.