The kinetics of the Fischer-Tropsch synthesis and water gas shift reactions over a precipitated iron catalyst were studied in a 5 channel fixed-bed reactor. Experimental conditions were changed as follows: synthesis gas H2/CO feed ratios of 0.5~2, reactants flow rate of 60~80 ml/min, and reaction temperature of 255~275 ℃ at a constant pressure of 1.5 MPa. The reaction rate of Fischer-Tropsch synthesis was calculated from Eley-Rideal mechanism in which the rate-determining step was the formation of the monomer species (methylene) by hydrogenation of associatively adsorbed CO. Whereas water gas shift reaction rate was determined by the formation of a formate intermediate species as the rate-determining step. As a result, the reaction rates of Fischer-Tropsch synthesis for the hydrocarbon formation and water gas shift for the CO2 production were in good agreement with the experimental values, respectively. Therefore, the reaction rates (rFT, rWGS, -rCO) derived from the reaction mechanisms showed good agreement both with experimental values and with some kinetic models from literature.