The study was done for high-pressure adsorption of methane on microporous carbons, which has an ANG vehicular application background. Adsorption isotherm of methane on super activated carbon up to 6 MPa was measured and isosteric heats of methane adsorption on a number of microporous carbons were determined from adsorption isosteres by the Clausius-Clapeyron equation. The variation of the isosteric heats of adsorption with the amount of methane adsorbed was discussed.