The present invention provides a method for measuring the concentration of an analyte in a test solution wherein the analyte is mevalonic acid and/or 3-hydroxymethylglutaryl coenzyme A, comprising the following steps (p) and (q): (p) a step of allowing an enzyme that catalyzes a reaction represented by Reaction Formula 1 and an enzyme that catalyzes a reaction represented by Reaction Formula 2 to act on a test solution containing mevalonic acid and/or 3-hydroxymethylglutaryl coenzyme A in the presence of a hydrogen acceptor X, a hydrogen donor Y, and coenzyme A; and (q) a step of measuring an amount of: a reduced hydrogen acceptor X that is produced; or an oxidized hydrogen donor Y that is produced; or a hydrogen acceptor X that is decreased; or a hydrogen donor Y that is decreased, wherein the hydrogen donor Y and the reduced hydrogen acceptor X are not the same.