Aim To elucidate the proatherogenic effect of oxidized low density lipoprotein (ox-LDL)on the apoptosis of cultured endothelium cells and protect effect of nimodipine. Methods ox-LDL was obtained by incubated with Cu²⁺ ,different concentrations of ox-LDL incubated with endothelium cells. MTT test was carried out to evaluate the cell growing state. PI staining test and ELISA test were conducted to analyze apoptosis index. Results The inhibiting effect of ox-LDL on the endothelium growth by ox-LDL was in a dose- dependent manner. ELISA and PI staining showed that ox-LDL induced endothelium cell apoptosis at the same concentration (P<0.05), Nimodipine could inhibited the ox-LDL induced endothelium cell apoptosis. Conclusions The cytotoxicity of ox-LDL to endothelium cell was related to the dosage concentration of ox-LDL: the ox-LDL could inhibit the cultured endothelial cells growth,and even resulted in apoptosis. ox-LDL could start the atherosclerosis in vivo due to the endothelium cells impairment and apoptosis.Nimodipine could protect endothelium from ox-LDL induced apoptosis.