The electrical properties of alkali ions exchanged zirconium hydrogen phosphate Zr(HPO 4) 2·H 2O (α-ZrP) are investigated by impedance spectroscopy technique. Cole–cole plots are used to describe the characteristic changes of electrical properties with relative humidity. The evaluated bulk resistance from the equivalent circuit shows exponential dependence of relative humidity. The surface protons of layered (α-ZrP) contribute to electrical conduction. The largest sensitivity is obtained for K ion exchanged systems.