Benzene was formed selectively among hydrocarbons produced in CH4-CO reaction over silica supported Rh, Ru and Pd catalysts at 573-723 K under atmospheric pressures, although CO2 was the main product, which was formed jy the disproportionation of CO. Addition of H-2 to CH4-CO reaction accelerated the rate of benzene formation several times, and the selectivity increased considerably.