Abstract: The catalytic performance of CuO/ZnO/CeO₂/ZrO₂ prepared by co-precipitation for methanol steam reforming was investigated using a statistical set of experiments in order to optimize the reaction conditions for obtaining minimal carbon monoxide in the reformed gas. The reaction temperature, steam to methanol ratio, methanol gas hourly space velocity (GHSV) were evaluated with a full factorial design experiment. The reaction temperature displayed much greater influence on the response (methanol conversion and CO concentration in reformed gas), GHSV has minimal influence on the CO concentration in reformed gas. At a fixed low methanol GHSV (300 h^-1), a central composite rotatable design was then used to approximate the optimal conditions by simultaneously considering the methanol conversion and CO concentration. The optimum theoretical conditions were found to lie within a reaction temperature of 249~258℃ and a W/M ratio of 1.76~2.00, in close agreement with the experimental results.