Provided is a catalyst used for a living radical polymerization method, which contains a central element consisting of carbon and at least one halogen atom binding to the central element. Further, a hydrocarbon compound can be used as a catalyst precursor. A monomer having a radical-reactive unsaturated bond is subjected to a radical polymerization reaction in the presence of the catalyst, consequently a polymer having narrow molecular weight distribution can be obtained, and thus the cost of the living radical polymerization can be remarkably reduced. The present invention is significantly more environmentally friendly and economically excellent than conventional living radical polymerization methods, due to advantages such as low toxicity of the catalyst, low amount of the catalyst used, high solubility of the catalyst, mild reaction conditions, and no coloration/no odor (no need of any post-treatments for a molded article), and the like.