Abstract: In order to describe the moisture transport process in the cellular tissues of fruits and vegetables during drying, the mass transfer processes of porous media drying and their related mathematical models were reviewed in this article. Based on the physiological structures and characteristics of fruit and vegetable tissues, a new concept for mass transfer of drying process was presented and the related parameters in the mathematical model were determined by means of microscopic images and convective drying experiments. The transmembrane transport model developed in this article estimated the water transfer process form the intracellular to the intercellular spaces effectively. The results showed that about 90% of the water present in the cells. Sequence of water migration in plant tissue during drying process was that water outflows from vacuoleto intercellular space (pores), which could be estimated by the water transmembrane flux(JV); and then water diffusion inside the pores of plant porous media could be calculated by the conventional pore network models.