A first problem is to provide a novel technique for forming hyaluronan into particles. Further, a second problem is to provide a novel technique suitable for production of a composite particle containing an anionic polymer and a peptide.Means for solving the first problem is a composite particle containing an anionic polymer, and a cationic polymer (except for chitosan) having a degree of cationization of 0.2 or more. Means for solving the second problem is to mix an anionic polymer and a peptide in an aqueous solvent having a pH of 5 or less.
