Abstract: Hydrogen production by catalytic steam reforming of methanol over a series of coprecipitated Cu/ZnO/Al2O3 catalysts under atmospheric pressure in a microreactor has been studied. Effects of catalyst composition, reaction temperature and activation conditions on the catalytic activity have been investigated. Crystal phases of catalysts were analyzed by XRD. The results showed that Cu/ZnO/Al2O3 catalysts displayed high activity and selectivity for hydrogen and stability. The optimized molar ratio is Cu/Zn=1.0, a maximum methanol conversion of 99.4mol%, hydrogen selectivity of 99.9 mol% and CO molar fraction of 0.007% were obtained in the steam reforming reaction with the catalyst containing 45 mol% copper. XRD results showed that the diffraction peaks of CuO in the catalyst were clearly lower and broaden. It indicated that high dispersion of small copper crystallites on the catalyst surface was formed under the calcination conditions. It is suggested that the good performance of Cu/ZnO/Al2O3 catalysts partly resulted from well dispersed copper.