Non-stoichiometric titanate CsxTi2-x/4O4 is a layer structured compound with the lepidocrocite (FeO(OH)) related structure. Cs+ in the interlayer space of Cs0.68Ti1.83O4 (x = 0.68 in CsxTi2-x/4O4) is quantitatively ion exchanged with hydrated H+, Li+ and Na+ using aqueous solutions of HCl, LiCl and NaCl. The compositions and the lattice constants of the resulting products were revealed by chemical analysis, TG-DTA and XRD measurements. Ionic conductivity was measured by ac impedance technique in the temperature range of -30 to 30 degrees C. The conductivities at 0 degrees C are 5.2 x 10(-7), 6.4 x 10(-6) and 9.8 x 10(-6) Scm(-1) with the activation energies of 10.3, 18.0 and 16.8 kcal mol(-1) for the H+, Li+ and Na+ exchange products, respectively. These conductivities are comparable to those of the layered clay minerals of vermiculite and montmorillonite in which mobile cations are hydrated.