The levels of plasma high density lipoproteins (HDL) are inversely related to the incidence of atherosclerosis and coronary heart disease. This protective effect of HDL is thought to be involved in the reverse transport of cholesterol from peripheral tissue to the liver. The scavenger receptor class B type 1 (SR-BI) is the first HDL receptor that can mediate the selective uptake of HDL cholesterol in steroidogenic tissues and in liver. The expression of SR-BI in liver appears to be responsive to changes in the hormonal status and in the levels of HDL cholesterol. However, long-term effects of high-cholesterol diet on the SR-BI expression in liver parenchymal cells and KupfFer cells have not been studied. to investigate the in vivo effects of liver-specific SR-BI expression on lipid metabolism, we fed male Sprague-Dawley rats with high-cholesterol or normal diet for 1 and 12 months.