PROBLEM TO BE SOLVED: To provide a novel preparation method of cosmetics for improving a skin state.SOLUTION: The invention provides a preparation method of cosmetics selecting a specific enzyme, and optimizing the amount of oil components of the cosmetics using the enzyme activity of the enzyme concerned as an indicator. Preferably the enzyme in a horny layer contains one kind selected from kallikrein 5, caspase-14, catalase, and NADH dehydrogenase. The skin state improving effect of the cosmetics can also be evaluated by using these enzymes as an indicator.