Abstract: The global reaction rate of benzene hydrogenation to cyclohexane accompanied by partial internal wetting of catalyst pellets was measured by a new method, which investigated both adsorption and chemical reaction.The adsorption investigation was used to establish a relationship between the extent of liquid filling of the catalyst and the bulk conditions while the chemical reaction investigation was to study the effect of partial internal wetting of the catalyst on the global reaction rate.It was shown that the extent of liquid filling in the catalyst interior showed a significant effect on the global rate, and the current state of the catalyst depended on the history, i.e. whether it was a liquid evaporation process or a vapor condensation process, and two steady states were found under certain circumstances.A mathematical model was developed, which took multicomponent diffusion, chemical reaction, pore size distribution of the catalyst and capillary condensation of condensable components in the catalyst pellet into consideration.The predicted values were in good agreement with the experimental data.