Abstract: This invention concerns novel mevalonolactone derivatives having the formula ##STR1## wherein A represents a direct linkage, methylene, ethylene, trimethylene or vinylene group; R.sup.1 represents hydrogen atom, an aliphatic acyl group, benzoyl group, or a benzoyl group substituted with hydroxy, lower alkoxy, aliphatic acyloxy or halogen; R.sup.2 represents hydrogen atom, a halogen atom or methyl group; and R.sup.3, R.sup.4 and R.sup.5 are same or different and each represents hydrogen atom, a halogen atom, a lower alkyl group with or without halogen as the substituent, phenyl group, or a phenyl group substituted with halogen, lower alkoxy, aliphatic acyloxy or lower alkyl with or without halogen, or a group represented by the formula R.sup.6 O-- (in the formula, R.sup.