Cobalt-copper oxalate and cobalt oxalate nanofibers were synthesized by a simple precipitation method and further examined as catalysts for the heterogeneous Fenton reaction. It was found that experimental parameters including initial pH of pollutant solution, concentrations of CR and H2O2, and reaction temperature affected the degradation of CR. Under optimized conditions of catalyst loading = 100 mg L-1, pollutant concentration = 100 mg L-1, H2O2 concentration = 3 wt%, temperature = 30 °C and pH = 9, the Cobalt.copper oxalate nanofibers could completely degrade the Congo red within 100 min. The degradation products were analyzed and the degradation pathway was revealed. Mechanistic studies revealed that hydroxyl radicals derived from the activation of H2O2 by metal centers were mainly responsible for the degradation of CR, and that copper played a critical role in the superior catalytic performance of cobalt-copper oxalate.