Aim To investigate the effects of nicotinic acid on the atherosclerotic plaques formation and osteopontin （OPN） mRNA expression of aorta. Methods 16 New Zealand white rabbits were fed with high-fat diet for 8 weeks,and then were randomly divided into two groups: （1）hyperlipidemia group （n＝8）: maintained high-fat diet for 6 weeks （2）niacin treatment group （n＝8）: the same fat diet supplemented with niacin ［200 mg/（kg·d）］ for 6 weeks. Control group （n＝8） was fed with normal diet for 14 weeks. At the end of the study,all rabbits were sacrificed to detect the histopathological changes and OPN mRNA expression of the aortas. Results Rabbits fed with high-fat diet showed more aorta endometrial thickness,plaque area and OPN mRNA expression （all P<0.01）. Compared with hyperlipidemia group,rabbits treated with niacin showed less aorta endometrial thickness,plaque area and OPN expression （all P<0.01）. Correlation analysis suggested that expressions of OPN mRNA （r＝0.888,P<0.01） and OPN protein （r＝0.821,P<0.01） were positively correlated with area of atherosclerotic plaque,expressions of OPN mRNA （r＝0.874,P<0.01） and OPN protein （r＝0.818,P<0.01） were also positively correlated with intimal thickness of aorta. Conclusion Niacin’s role of anti-atherosclerosis not only is due to its lipid-lowering effect,but also may be related to its OPN expression-lowering effect.