AimTo study the effect of dalteparin on the renal artery atherosclerotic lesion formation in the apolipoprotein E knockout (Apo E-/-) mice.Methods36 male Apo E-/- mice，6 weeks，fed with high-fat diet,were randomized into three groups: control group,dalteparin low dose group［100 IU/（kg·d)］, dalteparin high dose group［200 IU/（kg·d）］.24 male C57BL/6J mice，6 weeks，were randomized into two control groups:nomal diet group and high-fat diet group.At 12 weeks Apo E-/- mice were received dalteparin treatment for 4 weeks,then six mice of each group were killed.Light microscopy was adopted to assess the degree of the atherosclerotic plaque of renal artery wall and image analysis was performed with computer.The expressions of lectin-like oxidized LDL receptor-1(LOX-1) in aortic wall were studied by immunohistochemistry and Western Blot.The expressions of LOX-1 mRNA and vascular endothelial growth factor（VEGF）mRNA were studied by RT-PCR.The rest mice were fed with the same diet as before for another 4 weeks,then were killed.Light microscopy was adopted to assess the degree of atherosclerotic plaque of renal artery.Results