Objective:To explore the function of MDM2 and its relationship with p53 at the cellular level during H 2O 2 induced oxidative damage. Methods:MLE-12 HALI cell models were established using 0.5 mmol/L H 2O 2, and were divided into three groups: normal control group, H 2O 2 injury group, H 2O 2+MDM2 overexpressed group, and H 2O 2+MDM2 shRNA group. Infection of MLE-12 cells with adenovirus vector overexpressing and silencing MDM2; Using immunoprecipitation (Co-IP) to analyze the interaction between MDM2 and p53; Western blotting was used to detect the protein expression levels of MDM2, p53, Bcl-2, Bax, and cleared caspase-3 after HALI modeling; Measure the apoptosis rate of cells in each group. Results:After transcriptome sequencing,the p53 signaling pathway closely related to HALI. Compared with the normal group, the expression of MDM2 in the H 2O 2 injury group was lower ( P<0.05); Compared with the H 2O 2 injury group, overexpression of MDM2 resulted in a decrease in the apoptosis rate of MLE-12 cells ( P<0.05), a decrease in the expression levels of p53, Bax, and cleared caspase-3 proteins, and an upregulation of MDM2 and Bcl-2 protein expression ( P<0.05). Compared with the H 2O 2 injury group, when MDM2 was silenced, the cell apoptosis rate increased ( P<0.05), and the expression levels of p53, Bax, and cleared caspase-3 proteins were upregulated, while the expression levels of MDM2 and Bcl-2 proteins decreased ( P<0.05). Co-IP experiments showed that MDM2 binds to p53 protein. Conclusions:MDM2 can exert a protective effect on HALI by inhibiting MLE-12 cell apoptosis through the p53/Bcl-2/Bax axis.