In this paper, Fe3O4-Mn3O4/reduced graphene oxide (RGO) hybrid was synthesized through polyol process and impregnation method and used as heterogeneous Fenton-like catalyst for degradation of sulfamethazine (SMT) in aqueous solution. The hybrid catalyst had higher catalytic efficiency compared with Fe3O4-Mn3O4 and Mn3O4 as catalyst for degradation of SMT The effects of pH value, H2O2 concentration, catalyst dosage, initial SMT concentration and temperature on SMT degradation were investigated. The removal efficiency of SMT was about 98% at following optimal conditions: pH = 3, T = 35 degrees C, Fe3O4/Mn3O4-RGO composites =0.5 g/L, H2O2 = 6 mM. The inhibitor experiments indicated that the main active species was hydroxyl radicals (center dot OH) on catalyst surface. At last, the possible catalytic mechanism was proposed. (C) 2016 Elsevier B.V. All rights reserved.