Tin dioxide (SnO 2 ) behaves excellent properties, but the high recombination rate of photoexcited electron-hole pairs combined with a large band gap restricts its photocatalytic applications. Comparing with pure SnO 2 nanospheres, the photocatalytic degradation of rhodamine B (RhB) over polymer/reduced graphene oxide (rGO)/SnO 2 composites was enhanced. For the synthesis, graphene oxide (GO) nanosheets were wrapped on the surface of polymer microspheres to form a polymer/GO core-shell structure. Then, SnO 2 nanospheres were decorated on polymer/GO microspheres under a hydrothermal condition, meanwhile GO was reduced to rGO. Therefore, polymer/rGO/SnO 2 hierarchical structure was obtained. As graphene promote separation of the photoexcited electron-hole pairs and the conduction band potential of SnO 2 is more positive than the work function of graphene, electrons can be quickly transferred to the conduction band of SnO 2 via graphene leaving over more holes on the surface of catalyst for the de-ethylation of RhB.