The transport structural parameters system to characterize the ion-exchange membranes has been suggested on the basis of inhomogeneous structure model and generalized conductivity theory. We propose the transport structural parameters (TSP) system, which contains the structural parameters f and alpha and transport parameters kappa(iso) and G, characterizing the ions transport in the phase I of the membrane material. It is shown that the concentration dependencies of electroconductivity and diffusion flux in the wide range of salt solution are basic to membrane characterization. The equations to transport structural parameters (TSP) calculation/are presented. Results of TSP determination for a lot of membrane materials of the different structural types are discussed. The key role of the membrane hydrate capacity influencing on the TSP values and their interrelations is demonstrated. The approach is useful both for description of the membrane electrotransport properties and for stating and solving of the dynamic problems of electrodialysis. (C) 2004 Elsevier B.V. All tights reserved.