This study experimentally explores hydrogen concentration, methanol conversion efficiency, and CO concentration for a methanol steam reformer heated by catalytic oxidation of methanol. Before starting the methanol steam reforming, the study first observed how methanol of volume rate and air/fuel ratio affect temperature variation of oxidized methanol in the burner. The methanol steam reforming was then conducted using the better volume rate and air/fuel ratio of the methanol for heating. The reforming aqueous methanol is varied by volume rate, water to methanol mole ratio (S/C) and reforming reaction temperature. When the reforming reaction temperature is higher than the set temperature, the supply of methanol in the burner will be cut off by a proportional-integral-differential controller. The results for oxidation of methanol show that the temperature of oxidized methanol rises with increasing volume rate of methanol and increases but later decreases with air/fuel ratio. The more the volume rate of methanol is, and the faster the reforming reaction temperature is obtained. The results for methanol steam reforming indicate that as the reforming reaction temperature increases, hydrogen concentration and methanol conversion efficiency increase. The higher S/C helps to increase hydrogen concentration but decrease CO concentration. (200 words).200 words).