Manganese oxide catalysts modified by Mg, Ca, Sr and Ba additives were studied for methane deep oxidation. The Ba promoted sample is the most effective one for this reaction among all the catalysts. The catalysts were examined by BET, XRD and H-2-TPR techniques. It is speculated that the formation of some more active oxygen species and the formation of basic sites from the addition of alkaline earth metal oxides are responsible for the improvement of the inherent CH4 oxidation activity of the modified catalysts.