In this study the catalytic conversion of methanol to propylene (MTP) over Mn-modified desilicated HZSM-5 catalyst was evaluated in an experimental fluidized bed reactor in the reaction temperature range 450-540 degrees C and inlet gas velocity of 1.5-3 times greater than the minimum fluidization velocity. Although both the change of temperature and the inlet gas velocity affect the methanol conversion, the results showed that the former significantly influences the product yields, while the latter does not have such an effect (over the studied ranges). Additionally, a six-lumped kinetic model was developed based on the integration of hydrocarbon pool and olefin-based cycle mechanisms to describe the reaction pathway. To estimate the kinetic parameters from the experimental data using a hybrid genetic algorithm, the kinetic model was coupled with a two-phase structure hydrodynamic model. This coupled model can accurately predict the methanol conversion and product yields in a fluidized bed, where the root-mean-square error (RMSE) is equal to 0.95%. The results of modeling indicate that the maximum propylene yield (52%) can be obtained at maximum temperature studied (540 degrees C) over the whole studied range of velocity. By applying this condition, a methanol conversion of about 99% was obtained.