The synthesis of an n-type π-conjugated hyperbranched polymer, hyperbranched polypyridine, is described. The polymer is obtained by copolymerization of 2,4,6-tribromopyridine and 2,5-dibromopyridine via chain-growth condensation polymerization catalyzed by Ni(dppp)Cl2. The NMR and fourier transform infrared results indicate the successful introduction of the branching unit into polypyridine by this cross coupling approach. The results of UV窶砺is spectroscopy and cyclic voltammetry suggest that the introduction of the branching unit contributes to a quick response during electrochemical doping due to the diffusion of dopant enhanced by the hyperbranched structure.