Ultrafine Europium-doped yttrium aluminum garnet (YAG:Eu 3+ ) phosphor powders, with uniform diameters of about 1 μm, have been prepared by metallorganic chemical vapor deposition (MOCVD). The metal–organic precursors have been characterized by thermogravimetry–differential scanning calorimeter (TG–DSC). The phosphor powders have been identified by X-ray diffraction (XRD), scanning electron microscope (SEM) and photoluminescence measurements. It shows that the YAG:Eu 3+ particles annealed at 1473 K for 3 h are nonaggregated and spherical, the diameter of particles is in the range of 1–2 μm. Phase-pure YAG which is of spherical shaped particles have been obtained and observed good luminescence property. Three major emission peaks were observed at 589, 594, and 607 nm.