CuAl₂O₄ and CuAl₂O₄：Cr phosphors were prepared by a mild sol-gel method with tartaric acid as chelating agent.The X-ray powder diffraction results showed that the CuAl₂O₄ xerogel sintered at 800 ℃ exhibited a pure cubic CuAl₂O₄ phase with high crystallinity,CuAl₂O₄：Cr phosphor after sintering of xerogels was a mixed phase of CuAl₂O₄ and Cr₂O₃.The analysis of elemental composition and charge state showed that the CuAl₂O₄ and CuAl₂O₄：Cr phosphors did not contain other impurity elements,and there was a small amount of adsorbed oxygen in the two samples.Scanning electron microscope analysis showed that the particles of CuAl₂O₄ and CuAl₂O₄：Cr phosphors were approximately spherical,and each large particle was composed of many fine grains.The agglomeration phenomenon among CuAl₂O₄：Cr phosphor particles was obvious than that of CuAl₂O₄.The optical properties analysis found that the agglomeration of CuAl₂O₄：Cr phosphor particles resulted in a smaller optical band gap than that of CuAl₂O₄.CuAl₂O₄：Cr phosphor stimulated at 255 nm,and a strong fluorescence emission peak was obtained at 690 nm,which was mainly attributed to the transition between²E_g and⁴A_2g in Cr³⁺.