Li-7 (-) (x)La(3)ZT(2)O(12) (- 0.5x) (LLZ) ceramics with garnet-type structure were prepared via the conventional solid-state reaction method. The results showed that the sintering temperature has a significant effect on the crystal structure and phase composition, and thus ionic conductivity, of the LLZ ceramics. The ionic conductivity at room temperature of the ceramic samples increased with the crystal structural transition from tetragonal to cubic structure, as the sintering temperature increased; and reached a value of about 3.6 x 10(-4)S/cm for the cubic LLZ sample sintered at 1230 degrees C, but LLZ would be decomposed at 1250 degrees C. (C) 2011 Elsevier B.V. All rights reserved.