The mechanism outlined in literature for methane steam reforming over nickel catalysts is reviewed. Activation energy of this set of elementary steps for methane conversion into synthesis gas is obtained on the basis of bond order conservation Morse potential (BOC-MP), and the pre-exponential factors of the rate expressions of these elementary steps are then estimated according to the reported ranges in literature. A real-time Monte Carlo approach is developed to simulate the micro-kinetic trends for this catalytic process.