Millimeter-scale translucent La2O3-doped Al2O3 ceramic hollow spheres have been successfully prepared using the oil-in-water (paraffin-in-alumina sol) droplets as precursors made by self-made T-shape micro-emulsion device. The main crystalline phase of the obtained hollow sphere is alpha alumina. The prepared translucent La2O3-containing Al2O3 ceramic hollow spheres have diameters of 500-1300 mu m, wall thickness of about 23 mu m and the degree of sphericity of above 98%. With the increase of the La2O3 content, grains and grain-boundaries of the alumina spherical shell for the prepared millimeter-scale hollow spheres become regular and clear gradually. When the La2O3 content is 0.1 wt.%, the crystal surface of the obtained Al2O3 spherical shell shows optimal grains and few pores, and its transmittance reaches 42% at 532 nm laser light. This method provides a promising technique of preparing millimeter scale translucent ceramic hollow spheres for laser inertial confined fusion. (C) 2015 Elsevier Ltd. All rights reserved.