Cu-Mn and Ag-Mn composite oxide catalysts were prepared by the modification of high specific surface area MnO2 precursor with Cu or Ag, and used for CH4 deep oxidation. The results were compared with that of unmodified MnOx. It is found that both Cu and Ag additives increase the oxidation activity of manganese oxide below 420 degreesC; however, only Ag lowers the CH4 complete oxidation temperature (T-98), whereas Cu increases the T-98 The catalysts were characterized by means of BET, XRD and H-2-TPR. Due to the synergetic effects of Cu and Ag ions with manganese oxide, the activity of the oxygen species is improved, leading to the increase of the oxidation activities of the modified catalysts, especially below 420 degreesC.