Abstract： Objective To explore the protective effect of erythropoietin (EPO) against oxidized-low density lipoprotein (ox-LDL)-induced apoptosis in human umbilical vein endothelial cells (HUVECs) in an ox-LDL induced apoptosis model. Methods Thirdsixth passage of cultured HUVECs were used,and they were divided into two groups. The cells were pretreated with different concentrations (6.25,50,100 kU/L) of recombinant human erythropoietin (rhEPO) for 24 hours,then they were exposed to ox-LDL (100 mg/L) for 48 hours;another group of cells were pretreated with antisense to 0.5 μmol/L LOX-1 mRNA or 0.5 μmol/L sense for 24 hours,and then HUVECs were exposed to ox-LDL (100 mg/L) for 12 hours. Apoptosis was assessed by the apoptosis ratio,cell viability,and Bcl-2/Bax ratio. Results As compared to untreated controls,pretreatment with rhEPO led to increased cell survival of HUVECs and decreased cell apoptosis in a dose-dependent manner (all P<0.05). Consistently,the Bcl-2/Bax ratios were also increased in a similar fashion. The ratio of apoptosis protein Bcl-2/Bax was increased in the antisense LOX-1 mRNA group than that of ox-LDL group (P<0.05),but the one in the sense LOX-1 mRNA group was not significantly different from that of ox-LDL group. Conclusion The ox-LDL can induce apoptosis in HUVECs by regulating LOX-1 mRNA,and rhEPO can increase Bcl-2/Bax ratio and inhibite ox-LDL-induced apoptosis of HUVECs.