目的以小鼠肺组织中ＴＧＦβ１含量变化为指标，观测高低氧（ＨＯ＋ＬＯ）照射对肺晚期损伤的生物学效应。方法雄性Ｃ５７ＢＬ小鼠，１３Ｇｙ全肺一次照射，照射同时分别吸入空气、高氧（９５％Ｏ２＋５％ＣＯ２）或高低氧（１０％Ｏ２＋５％ＣＯ２＋８５％Ｎ２），照射后不同时间取肺组织ＨＥ染色、Ｍａｓｏｎ染色、Ｖ．Ｇ．染色观察肺纤维化形成。ＲＴＰＣＲ方法测定肺组织内ＴＧＦβ１的表达。结果照射后８个月肺组织局部灶性纤维化形成。高氧组肺纤维化面积大于空气组及ＨＯ＋ＬＯ组，两者相比，差异具有显著性；ＨＯ＋ＬＯ组纤维化面积虽略高于空气组，但差异无显著性。照射后３６小时，ＴＧＦβ１表达下降，照射后２个月，ＴＧＦβ１表达升高，至照射后８个月，略呈下降趋势，但仍高于正常对照。结论低氧的加入降低单纯高氧导致的正常组织损伤，ＨＯ＋ＬＯ照射不增加肺的晚期损伤，ＴＧＦβ１的表达在肺纤维化形成过程中起重要作用 Objective To investigate the biological effects of high  hypoxia (HO + LO) irradiation on the late lung injury in mouse lung tissue. Methods Male C57BL mice, 13 Gy whole lung single irradiation, irradiated simultaneously the intake air, high oxygen (95% O2 + 5% CO2) or high  hypoxia (10% O2 + 5% CO2 + 85% N2), after irradiation at different time lung tissue HE Staining, Mason staining, V. G. Staining observed pulmonary fibrosis. RT  PCR method for determination of TGF  β1 expression in lung tissue. Results Pulmonary tissue focal fibrosis was formed 8 months after irradiation. The area of ​​pulmonary fibrosis in hyperoxia group was larger than that in air group and HO + LO group, the difference was significant. The area of ​​fibrosis in HO + LO group was slightly higher than that in air group, but the difference was not significant. 36 hours after irradiation, TGF β1 expression decreased 2 months after irradiation, TGF β1 expression increased to 8 months after irradiation, a slight downward trend, but still higher than the normal control. Conclusion The addition of hypoxia caused by high oxygen reduction simply damage to normal tissue, HO + LO advanced without increasing the irradiation damage to the lungs, during play an important role in the expression of pulmonary fibrosis formed TGFβ1