The methane reforming with and steam for manufacture of synthesis gas over catalyst was investigated. Mixed reforming carried out dry reforming with and steam for development of DME process in pilot plant. To improve a catalyst deactivation by coke formation, the mixed reforming added carbon dioxide and steam as a oxidizer of the methane reforming was suggested. The result of experiments over commercial catalyst in dry reforming has shown that the catalyst activity decrease rapidly after 20 hours. In case of catalyst, the deactivation of 20 percent after 30 hours was occurred. The activity of Ni/C catalyst still was not decreased dramatically after 100 hours. The effect of reforming with steam over catalyst obtained the optimal conversion of methane and carbon dioxide, and could be produced synthesis gas at ratio of under 1.5.