Oxidative coupling of methane （OCM） was carried out over Na⁺-ZrO₂-Cl/Al₂O₃ catalysts in a temperature range from 1023 to 1123 K. The catalysts were prepared by impregnating the Ձ- or Ճ-Al₂O₃ supports with sodium carbonate and/or zirconyl chloride. The OCM activity was examined using the catalysts prepared by three different preparation procedures. The best catalyst was the one prepared by subsequent impregnation of sodium carbonate-preimpregnated Ճ-Al₂O₃ with a mixed solution of sodium carbonate and zirconyl chloride. It was found that preimpregnated sodium played an important role in reducing the combustion activity of the Ճ-Al₂O₃. The catalyst with an optimal composition showed the highest C₂ selectivity and yield of 40.8% and 15.1% respectively. From the X-ray diffraction analysis it was found that tetragonal ZrO₂ was formed and that NaCl existed in the catalysts with relatively high sodium contents.