Porous materials have been widely used because of their important applications: biomaterials, filtering and purifications systems, acoustic and thermal insulation, building constructions, transportation, communications, aeronautical applications, etc.To explain the formation mechanism of the porous structure materials, a multi-scale mathematical model for diffusion coupling with dissolution and crystallization is proposed in which the chemical potential gradient is used as the driving force to avoid the discontinuity of the kinetics equations in the mi cro-channels.