Abstract: The interactions between the transport, reaction, pore morphology and evolution process are analysed in this paper. A fractal pore model is presented. These local fractal pores are the constituents of the pore network of char particle. The Bethe network is used to describe the pore space topology of the medium. This approach provides a natural framework for characterization of the geometrical structure of the pore and modelling of pore opening , enlargement and coalescence in the evolution of porosity and internal accessible surface area with the process of char gasification. This study also considers the loss of solid fragments by percolation. So it is applicable to modelling the char gasification proceas in the industrial gasifier.