Aim To investigate the change of aortic atherosclerosis and plasma adiponectin of apolipoprotein E knockout(ApoE-/-) mouse treated with piogitazone. Methods 9 male mice of C57BL,17 weeks aged,were fed with common food for 4 weeks as simple control group.In addition,31 same age male mice of ApoE-/-were fed with high fatty food for setting up atherosclerosis animal models,and these mice were divided into three groups at random including:model group only receiving high fatty food for 4 weeks,low-dose treated group receiving piogitazone administered via gastric tube at 10 mg/(kg·d) for consecutive 4 weeks,high-dose treated group receiving piogitazone administered via gastric tube at 20 mg/(kg·d) for consecutive 4 weeks.The change of aortic atherosclerosis and levels of plasma adiponectin,plasma lipids of all mice were analyzed. Results The plasma levels of total cholesterol, low density lipoprotein cholesterol and high density lipoprotein cholesterol in all ApoE-/-mice were significantly increased than those in control group(P<0.01);The plasma adiponectin level in model group was significantly decreased than that of control group,but the plasma adiponectin was elevated and the lesions of aortic atherosclerosis were inhibited in two treated groups,moreover,these change were more significant in highdose treated group(P<0.05). Conclusions Pioglitazone inhibits aortic atherosclerosis in ApoE-/-mice,and these effects may be related to plasma adiponectin level increasing.