Yttrium Lanthanum Oxide transparent ceramics were fabricated with (Y0.9La0.1)2O3 powders prepared by different methods. The growth characteristics, physical and chemical properties of the powders were investigated. The wet-chemical composite powders’ particle size was inhibited by La2O3 at high temperature treatment, therefore smaller than that of powders by solid-state reaction method. During the solid-state reaction between La2O3 and Y2O3 at temperature of 700~1100°C, La2O3 may have not effectively hindered the particle growth of Y2O3. (Y0.90La0.10)2O3 ceramic fabricated by both powders own smaller grain size and lower porosity than Y2O3 ceramics. The transmittance and sintering performance of Y2O3 ceramics were also improved after adding of La2O3. The powders prepared by both methods could be used to make high transparency ceramics.