Abstract: The model of liquid diffusion in a solid fractal medium is developed by adopting random theory, and thus the relationship of diffusion coefficient between fractal medium and free space is obtained. According to the study and analysis of micro-processes,the reaction mechanism and kinetics of liquid-solid phase which feature phosphoric acid and phosphate ore particles system are revealed. When the reactive components diffuse in the ore particle through a large amount of micro pores, there exist three zones, including penetration zone where reaction has finished, reaction zone where reaction and diffusion happen at the same time, and unreacted zone. With the reaction proceeding, the penetration and reaction zone will move towards the center of the particle. From the above basic point of view, the zone and fractal model of two-phase reaction kinetics model has been put forward.