Aim To investigate the role of endoplasmic reticulum stress （ERS）-mediated apoptosis in atherosclerotic calcification of diabetic apolipoprotein E gene knocked-out （ApoE^－/－） mice.Methods 6 weeks old male ApoE^-/- mice were first rendered diabetic by intraperitoneal injection of streptozotocin （STZ） for 5 days ［40 mg/（kg·d）］. After 2 weeks, the blood glucose level ＞3000 mg/L mice were included in this study, and then were given a semi-synthetic high-fat diet （HFD）, plus daily tail vein injection of carboxy methyl lysine （CML） ［10 mg/（kg·d）］. The mice were euthanized at 0 month （group 0M, n＝10）, 2 months （group 2M, n＝10）, and 4 months （group 4M, n＝10） after the triple administration of STZ-CML-HFD. Related detection and analysis were carried out for each group of mice. Results Morphological analysis showed that early atherosclerotic plaques appeared at 2 months after the triple administrations of STZ-CML-HFD, and that typically advanced plaques with extensive calcification lesions, abundant cholesterol crystals, and proliferative collagen were formed at 4 months after the triple administrations of STZ-CML-HFD. The intrinsic phenotype （SM22α） of aortic smooth muscle cells was gradually lost, and osteoblast-like phenotypes （bone morphogenetic protein-2, core binding factor α1, alkaline phosphatase） were increased. CML deposition signal and the expression of receptor for advanced glycosylation end product （RAGE） in the aortic wall were mainly restricted in the atherosclerotic plaques. Western blot assay showed the expressions of CML, RAGE and CD36 in aortic wall of diabetic ApoE^－/－ mice were significantly up-regulated, but the expression of ATP binding cassette transporter A1 firstly displayed a compensated increase and then reduced near the baseline. Experiment of TUNEL staining and cleaved caspase-3 immunohistochemical staining found intra-plaque cells apoptotic rate rised with the progression of diabetic atherosclerosis. Immunohistochemical location analysis showed glucose regulated protein 78 （GRP78）, a molecular chaperone of ERS and C/EPB homologous protein （CHOP） were mainly restricted in the lipid poor of atherosclerosis. Furthermore, compared with CHOP, the distribution signal of GRP78 in group 4M appeared more basal in lipid pool. Western blot semi-quantitative analysis found that the related indexes of ERS （GRP78, phosphorylated protein kinase RNA-like endoplasmic reticulum kinase, phosphorylated eIF2α, activating transcription factor 4, CHOP） were up-regulated with the extension of diabetic course in ApoE^－/－ mice.Conclusions STZ-CML-HFD combined intervention for 4 months can induce atherosclerotic calcification of diabetes in ApoE^－/－ mice. CML/RAGE may firstly start-up ERS-mediated apoptosis, and then cause to happen the calcification cascade signal.