Hyperbranched azo-polymer-grafted graphene oxide (GO) hybrid was synthesized. Epoxy-based precursor polymer was first covalently attached to GO through an ester linkage. Then the hyperbranched azo-polymer-grafted graphene oxide hybrid can be obtained by azo-coupling reaction between the epoxy-based precursor-polymer-functionalized GO and hyperbranched diazonium salts under extremely mild conditions.