Abstract: The catalytic properties of the Rh/γ-Al₂O₃ catalysts for the hydrogen-deuterium exchange of methane were tested with the fixed-bed micro-reactor. The conversion of methane is increased by increased reaction temperature when the temperature is less than 642 K, the conversion of methane is not changed with increasing temperature when the temperature is higher than 642 K at the same feed composition conditions. The conversion of methane is reduced with increasing the flow of reactants when the temperature is less than 642 K, the conversion of methane is not changed with increasing temperature when the temperature is higher than 642 K at the same feed composition conditions and the temperature 524-792 K. The conversion of methane is significantly reduced with increasing the HD/CH₄ flowrate ratio at HD/CH₄ flowrate ratio of 1.1-2.5, and the feed composition is changed in the range of total flow of reactants under the same conditions and the temperature of 524-792 K.