OBJECTIVE： To investigate the effect mechanism of diazoxide on the proliferation and apoptosis of chondrocytes with oxidative injury based on endoplasmic reticulum stress （ERS） pathway. METHODS： SD mice were selected for primary culture of articular chondrocytes. The 3rd generation chondrocytes were randomly divided into control group， injury model group and diazoxide group. Control group didn’t receive any treatment. The injury model group was incubated with 300 μmol/L hydrogen peroxide （H2O2） at 37 ℃ for 8 h. Diazoxide group was pretreated with 300 μmol/L diazoxide at 37 ℃ for 0.5 h，and then incubated with 300 μmol/L H2O2 for 8 h. The proliferation of chondrocytes was detected by CCK-8 assay. The apoptosis rate of chondrocytes was detected by flow cytometry. The expression of ERS-related proteins [Caspase-3， Bcl-2-associated X（Bax），C/EBP homologous protein （CHOP）] were detected by Western blotting assay. RESULTS： Compared with control group， the proliferation activity of chondrocytes in injury model group was significantly decreased， while apoptosis rate was increased significantly（P＜0.05）；the protein expression of Caspase-3， Bax and CHOP were increased significantly （P＜0.05）. Compared with injury model group， the proliferation activity of chondrocytes in diazoxide group was increased significantly， while the apoptosis rate was decreased significantly （P＜0.05）； the expression of above related proteins were decreased significantly （P＜0.05）. CONCLUSIONS： Diazoxide can improve the proliferation activity of chondrocytes with oxidative injury and inhibit their apoptosis by inhibiting ERS pathway.