Equilibrium and transport properties of ion-exchange electrodialytic membranes before and after their processing in model solution containing dimethylacetamide were investigated in LiCl solutions. Values of the membranes transport structural parameters reflecting structural and kinetic characteristics of the two-phase system were derived on the basis of electroconductivity and diffusion permeability concentration dependences of investigated membranes. Aprotic solvent influence on the properties of heterogeneous membranes and their transport structural parameters ware discovered.