Abstract: The water gas shift reaction over an environmental friendly iron-based shift catalyst NBC-1 was investigated in a fixed-bed plug flow microreactor at 618 K～723 K and 1.0 MPa. The microkinetics were evaluated by a power law kinetic model, which was found to give an excellent representation of the kinetic data. Comparatively, the activation energy of this catalyst is lower than that of the conventional iron-chromium for the water gas shift reaction, which has higher activity at lower temperature. The influence of H2O on the reaction rate is greater comparing with traditional ferrochrome shift catalysts, which may be resulted from the additional Ce component in this catalyst. The presence of CO2 in the reaction system results in the decrease of reaction rate greatly. It is crucial to reduce the resistance effect of the CO2 in favor of the water gas shift reaction rate. The influence of H2 on the reaction rate can be neglected.