A nanometal dispersion and a method for preparing a nanometal dispersion are provided. The method comprises mixing a metal seed crystal aqueous solution, a polysaccharide aqueous solution, and a metal compound aqueous solution, followed by allowing the resulting mixture to conduct a reduction-oxidation reaction to form a nanometal. The produced nanometal dispersion comprises a polysaccharide and a nanometal. The polysaccharide is composed of N-actyl-D-glucosamine and glucuronic acid, and the nanometal has multimorphology.