Kinetic analysis of acetylene hydrogenation over Pd-Mn/Al2O3 catalyst has been performed. Based on a set of data of stationary catalytic process and non-stationary experiments at 303–323 K, a reaction mechanism scheme is proposed. The overall process is found to proceed by two paths: the initial one comprises formation of an intermediate of C2H4Z2 type that may release C2H4 by acetylene attack (main reaction) or form ethane by hydrogen attack (minor reaction). The main and minor reactions are parallel ones. The second stage comprises consecutive C2H4 attack of adsorbed hydrogen with formation of C2H5Z species and their hydrogenation to ethane. This conclusive stage takes place at acetylene conversions higher than 75%. Kinetic description of two stages of acetylene hydrogenation has been developed and reaction constants are calculated. The activation energy of ethylene formation E2 equals to 64.9 kJ/mol. For conclusive stage of acetylene hydrogenation, the kinetic model developed gave rise to equation for description of selectivity-conversion dependence SC2H4 = f(XC2H2) up to XC2H2 = 100%. General factors for achieving high selectivity to ethylene have been formulated.