A series of saucerneol B derivatives 2a-i were prepared for evaluating their acyl-CoA: cholesterol acyltransferase inhibitory activities. Compounds 2a-g showed more specificity of hACAT-1 than hACAT-2. Saucerneol B (1) exhibited strong cholesterol-lowering effect in high cholesterol-fed mice. A series of 2a-i were prepared from a lead compound, saucerneol B (1) for evaluating their acyl-CoA: cholesterol acyltransferase inhibitory activities. Compounds 2a-g exhibited the high specificity of hACAT-1 than hACAT-2, whereas 2h and 2i showed very weak inhibitory activities in both hACAT-1 and hACAT-2. Saucerneol B (1) exhibited strong cholesterol-lowering effect in high cholesterol-fed mice.