Lens epithelial cells (LECs) apoptosis induced by oxidative stress is a major factor in age-related-cataract (ARC) pathogenesis, but there are still many blind nodes in this progress. This study aimed to investigate the effects of MDM2 phosphorylation in ARC and H2O2-induced lens epithelial cells apoptosis. Our results confirmed that the levels of p-MDM2 (Ser166) and p-MDM2 (Ser186) in the anterior lens capsules of human cataracts were reduced compared to that in normal capsules. Similarly, in naturally aging cataract mice, the level of MDM2 phosphorylation also decreased. Oxidative stress-induced apoptosis model was constructed by cultivating HLE-B3 cells with 200 mu M H2O2. It was confirmed that MDM2 could regulate lens epithelial cell apoptosis, and MDM2 inhibitors could partly inhibited AKT's role in suppressing apoptosis induced by H2O2. Besides, we examed the decreased level of p-AKT(Ser473) in apoptosis of lens epithelial cells and ARC. Our study revealed that MDM2 phosphorylation mediated H2O2-induced lens epithelial cells apoptosis and ARC, which could provide new ideas for the clinical treatment of ARC. (C) 2020 Elsevier Inc. All rights reserved.