Background Hyperhomcysteine was found to be an independent risk factor of coronary heart disease.But whether it really influenced the progression of atherosclerosis was not clearly demonstrated.In the present study we planed to learn about the concrete influence of hyperhomcysteine to the formation of atherosclerosis in low-density lipoprotein receptor-deficient mice.Methods Forty-eight 7-week-old low-density lipoprotein receptor-deficient mice were assigned to a controⅠ group fed a standard rodent diet, a high-metionine group fed a high-methionine diet, ahigh-fat group fed a high-fat diet,and a group on a diet both high in methionine and fat.At the age of 19 weeks, 23weeks, 27 weeks every four mice in each group were sacrificed.