Aim This study is to observe incidence and pathological changes of atherosclerosis for inbred NJS mouse strain in spontaneous hypercholesterolemia,and to investigate the biological property of the strain.Methods The aorta lesions waobserved by using original staining and tissue flat staining.Results The incidence of atherosclerosis of the strain was 100%in some liable positions such as aortic sac and ascending aorta at 8~10 months.Most of the lesions were in fatty streaks.It appeared stripy or flaky obviously on some red coloring positions by original staining.There were some foam cell in aortic wall by tissue flat staining. No pathological changes were seen at 2～3months of age.Conculsion Inbred NJS mouse strain can develop lesions of atherosclerosis. The strain can be used as a model atherosclerosis.