Objective To explore the expression of hypoxia inducible factor-1? and p53 in lung during hypoxia. Methods The mice were divided into two group (n=36,male,hypoxia group=36,control group=9).The hypoxia group mice were placed in a hypoxia chamber with 10%,7%,or 5% O 2 respectively.Immunofluorescent histochemical staining technique was used.The staining results were observed under the laser confocal scanning microscope. Results HIF-1? proteins didn't express and p53 proteins expressed weakly in control group mice; Compared with the controls,the expression of HIF-1? and p53 increased dramadically.There was significant difference in expression of HIF-1? and p53 between the hypoxia groups and the control group; Positive relationship was found between the expression of HIF-1? and p53. Conclusion The expression of HIF-1? and p53 increased in lung during hypoxia,which indicates that HIF-1? may play an important role in the expression of p53 and the regulation of apoptosis.;