There is provided a novel hyperbranched polymer in which the refractive index is precisely controlled while retaining its hyperbranched structure, and a method for producing the hyperbranched polymer. Further, there is also provided an optically and thermally stable novel hyperbranched polymer in which the desired refractive index is precisely controlled, and a method for producing the hyperbranched polymer. The hyperbranched polymer has, as a branched structure, a repeating unit structure produced from two dithiocarbamate compounds each having a vinyl structure, at the polymerization initiation site having a vinyl structure. A specific example of the hyperbranched polymer can be produced by subjecting to a living radical polymerization N,N-diethyldithiocarbamylmethylstyrene in the presence of N,N-diethyldithiocarbamylethyl methacrylate.