Coprocessing of bio-oil and petroleum fraction is a prospective way of bio-oil upgrading. The upgrading is a complex combination of kinetic and transport processes. An overall kinetic model was developed considering the internal diffusion and the catalyst deactivation in this paper. First, the parameters of intrinsic kinetics model were calculated by the experimental data obtained in a fixed-bed reactor with a fine powder catalyst particle (0.32 mm). Using the intrinsic kinetic parameters and gas-solid catalysis theory, an effectiveness factor model was developed to evaluate the effect of internal diffusion on coprocessing. Then the kinetic model r(B)=ax eta xr(B0) was established based on the effectiveness factor model and the deactivation rate equation. The effectiveness factor. and liquid yields at different reaction conditions predicted by this kinetic model agreed closely with the experimental results.