In the oxidative coupling of methane by carbon dioxide, La2O3/ZnO catalysts were found to have high C-2 selectivity and good stability. The coupling selectivity on La2O3/ZnO is about 90%, which is much higher than that on pure La2O3 or ZnO. The consumption ratio of carbon dioxide to methane is approximately one. X-ray diffraction analysis reveals that the structural forms of the oxides are unchanged during the reaction. The reaction mechanism for C-2 formation is discussed.