Abstract: The intrinsic and global kinetics of thiophene hydrodesulfurization over CoMo/Al2O3 catalysts were studied in an isothermal integral tubular reactor under the conditions of 543K~623K, 2.5MPa~3.5MPa and H2/oil mol ratio 2~4. The kinetic model was derived from the LangmuirHinshelwood mechanism and the kinetic parameters involved were estimated based on the experimental data. The kinetic model was verified by comparison of the experimental and predicted data as well as by statistical test. Moreover, the calculated Thiele modulus together with the comparison of the pore size distribution and the carbon content of the fresh catalyst with those of the deactivated catalyst revealed that the effect of the internal diffusion on the overall reaction rate was evident. The effectiveness factor was subsequently calculated from the intrinsic and global rates obtained above, and it showed that the effectiveness factor decreased dramatically with increased temperature, while the effect of H2/oil mol ratio was not evident.