Grafting of hyperbranched cyclotriphosphazene polymer (IMP) onto reduced graphene oxide (HBP-RGO) surface was achieved by the repeated reactions between the chlorine groups of hexachlorocyclotriphosphazene and the amino groups of hexamethylenediamine. FTIR and XPS analyses showed that hyperbranched cyclophosphazene-grafted graphene had been successfully prepared. AFM results showed that HBP-RGO had a dendritic structure as designed. TGA analysis indicated that HBP-RGO had good thermal stability. The dispersion showed that HBP-RGO is amphiphilic.