Methanol selective oxidation to methyl formate was investigated over ReOx/CeO2 catalysts in terms of Re loading and reaction mechanism. It was found that Re loading with monolayer dispersion on ceria exhibited promising reaction rate of methanol of 16 mmol g(cat.)(-1) h(-1) and methyl formate selectivity of about 90% at 513 K. The surface reaction of methanol, formaldehyde, and methyl formate over the ReOx/CeO2 catalyst was investigated by in situ Fourier transform infrared spectroscopy and it was revealed that the formate species, formed by the oxidation of adsorbed -OCH3 species, could act as the key reaction intermediate, which further reacted with gaseous methanol to form methyl formate and/or decompose into CO and CO2, depending on the reaction temperature.