Poly(sodium 4-styrenesulfonate) (PSSS) was grafted onto graphene oxide surfaces by surface-initiated atom transfer radical polymerization using CuBr/1,1,4,7,7-pentamethyldiethylenetriamine as the catalyst and N',N-dimethyl-formamide as the solvent. X-ray photoelectron spectroscopy, thermogravimetric analysis, scanning electron microscopy and transmission electron microscopy were used to verify the grafting of the PSSS chains and the partial reduction of graphene oxide during the grafting process. The PSSS grafted graphene oxide gives a stable aqueous dispersion even after being further reduced with hydrazine hydrate at 90 degrees C for 24 h. The reduced graphene oxide grafted poly (styrene sulfonic acid) which obtained from PSSS grafted graphene oxide had a good catalytic activity for the synthesis of isoamyl benzoate. (C) 2013 Elsevier B.V. All rights reserved.