Heat treatment is often used for improving the characteristics of heat and mass transfer of cork. In this study the effects of heat treatment on diffusion coefficient (Dapp) of Cork (Algeria cork) were examined, by the conductimetric method, and the influence on the treated chemical structure gave a decrease in this coefficient, this heat treatment offers more resistance to the mass diffusivity when compared with the corresponding natural cork in the direction of diffusion. The results found in isothermal conditions, faithfully represent the Arrhenius relationship.