From the impedance analysis, we report the dielectric constants of lithium triborate single crystals for the three principal axes in the frequency range of 100 Hz–1 MHz and in the temperature range of 303–773 K. The observed highly anisotropic behavior of dielectric dispersions is mainly related to the anisotropy of the activation energy forLi+ion hopping, which is constituted by theB3O7channel framework lain along thecaxis. ©1997 American Institute of Physics.