Abstract: A stable La₂O₃:Eu³⁺ red phosphor is prepared by composite precipitation method. The influences of the calcination temperature and the concentration of Eu³⁺ on the luminescent properties are studied. The crystal structure, particle size and morphology of the phosphor are characterized by X -Ray Powder Diffraction (XRD) and Scanning Electron Microscope (SEM) techniques. The luminescent properties of phosphor are measured by emission spectra, excitation spectra and decay curve. The results indicate that the as-prepared samples are La₂O₃:Eu³⁺ crystals of hexagonal phase by annealing at 900 ℃. The diameter of the particles of 5 % La₂O₃:Eu³⁺ is about 15 μm. The maximum emission and excitation wavelength are at 626 nm and 396 nm, respectively. The band at 596 nm and 626 nm are corresponding to ⁵D₀→⁷F₁ and ⁵D₀→⁷F₂ transition of Eu³⁺ ions in emission spectrum. The fluorescence lifetime of La₂O₃:Eu³⁺ phosphor is 0.754 ms.