The affinity of collagen for the skin and its persistence on the skin are improved without destroying the triple helical structure inherent in collagen to thereby improve its ability to retain the moisture of the skin and increase the amount of bound water when such collagen is used as a skin cosmetic. The collagen can thereby exert its moisture retention effect more effectively. A cosmetic base includes an aqueous solution of a liposome that is surface-modified with water-soluble collagen having a triple helical structure.
