The electrical conductivity and electron electrical conductivity of mordenite has been measured. The electrical conductivity and the activation energy of mordenite containing different water and ion-exchanged forms of mordenite have also been measured. The results show an ionic conductivity: the specific conductivity of mm denite is 10-6 to 10-5(Ω·cm)-1 in natural environment. The electrical conductivity of mordenite shows the change of its structure.