Samples of lanthanum lithium titanate with the general formula La 2/3 - x Li 3x TiO 3 with a different vacancy content, which is varied by varying the ratio of lanthanum to lithium, are investigated. Methods of synthesis, neutron diffraction data for the samples obtained, measurements of the lithium-ion conductivity of equilibrium and quenched samples, the results of nuclear magnetic resonance on 7Li nuclei, the dynamic characteristics of heat release (heat absorption), and the magnetic susceptibility of some samples are presented.