A stabilized dispersion of metal fine particles comprising, fine particles of metal which is obtained by reducing at least one metallic acid or salt thereof selected from the group consisting of haloauric acid, haloplatinic acid, silver nitrate and halorhodic acid by a reducing agent in the aqueous solution of (1) R-PEG-SX [R is a functional group selected from the group consisting of acetal, aldehyde, hydroxyl group, amino group, carboxyl group, active ester group, azide group, biotin group, monosaccharide, oligosaccharide, amino acid, nucleic acid, allyl group, vinyl benzyl group, methacryloyl group and acryloyl group, PEG is --(CH.sub.2CH.sub.2O).sub.n--, X is H or pyridylthio group] or (2) R-PEG/PAMA (given structural formula A), and said fine particles load a polymer having PEG unit possessing above mentioned functional group on the surface.