There are three competitive reactions in the removal of CO in reformate by methanation，including CO methanation，CO2 methanation and reverse water-gas shift（RWGS.Influence of several parameters such as reaction temperature，CO concentration and CO2 concentration on these reactions is studiedResults showed that both the CO and CO2 methanation rate increased with increasing temperature，while the selectivity for CO methanation decreasedWith higher CO concentration，the CO methanation appeared remarkably faster at higher temperature，and the CO2 methanation was notably depressed at lower temperatureThe selectivity for CO methanation increased with increasing CO concentration.On the other hand，the concentration of CO2 appeared no effect on the CO methanation，while both the CO2 methanation rate and the RWGS reaction rate increased when increasing the CO2 concentration，especially at higher temperature.The macro-kinetics of these three competitive reactions was also studied.