This invention relates to a class of novel phosphonate derivatives of lipophilic amines which exhibit squalene synthase inhibition properties. More specifically the compounds are bis aryl cycloalkylamino and azacycloalkyl phosphonates. Compounds of this invention reduce levels of serum cholesterol in the body without significantly reducing mevalonic metabolite synthesis. This invention relates also to pharmacological compositions and method of treatment for lowering serum cholesterol levels using the compounds of this invention.