Abstract: A self-cleaning stirred bed reactor with double axes was designed to carry out the study on kinetics of gas phase polymerization of butadiene with heterogeneous rare-earth catalyst, especially for solving the problems of 1,4- cis -polybutadiene particles agglomeration and sticking to the wall of reactor. The effect of diffusion resistance on polymerization rate was investigated.The influence of monomer sorption in microparticle was examined in order to determine the local monomer concentration on the polymer shell surrounding the active sites of the catalyst surface. Flory- Huggins’ sorption isothermal instead of classic Henry’s law was used to characterize the sorption of 1,3-butadiene on 1,4- cis -polybutadiene.Based on the experimental results including the effects of temperature and pressure on polymerization rate,an intrinsic kinetic model was proposed.The simulation result of the model was in good agreement with the experimental data.The model could be applied to similar heterogeneous catalyzed polymerization.