Abstract: The aim of this research is to study zirconia-based electrolyte materials to increase the commercial value of zircon concentrate as a side product of tin mining industries. Synthesis of CaO-Y₂O₃-ZrO₂ (CYZ) and 8mol% Y₂O₃-ZrO₂ (8YSZ) was carried out by solid state reaction. The result shows that ZrO₂ presents in tetragonal phase. Doping of Y₂O₃ into ZrO₂ allows a phase transformation from tetragonal into cubic structure with small percentage of monoclinic phase. Meanwhile, doping of CaO-Y₂O₃ allows a phase transformation into a single cubic phase. These phase transformations enhance the ionic conductivity of the material. Introduction of 10wt% of LSGM-8282 into CYZ (CYZ-L90:10) allows further improvement of inter-grain contact shown by SEM morphological analysis and leads to the enhancement of ionic conductivity.