There is provided a squalene inhibitory composition containing a 1,1-bisphosphonic acid compound, a lower alkyl ester thereof, or a salt thereof, which is useful for treating hypercholesterolemia. There are also provided novel compounds having squalene synthetase inhibitory activity and a pharmaceutical composition for treating hypercholesterolemia containing a 1,1-bisphosphonic compound, a lower alkyl ester thereof or a salt thereof.