Li7La3Zr2O12 (LLZ) ceramics with a garnet-type structure were prepared via the conventional solid-state reaction through different calcining processes. The calcining time and temperature were investigated. The results showed that the ionic conductivity of LLZ samples at room temperature decreased as the calcining temperature increased. The highest conductivity of 2.48 x 10(-4) S cm(-1) was obtained for the sample with the calcining process at 900 C. The amount of doping Al was also investigated, which showed different effects depending on the calcining process. (C) 2014 Elsevier B.V. All rights reserved.