LaLu0.7 Er0.3 O3 polycrystalline was synthesized by the co-precipitation method. It’s structure were determined by Rietveld refinement to X-ray powder diffraction, and the size of powder particles was also estimated. Its absorption and photoluminescence spectra at room temperature were measured. Under the excitation of 380 nm light, the 1.5 μm decay curve of Er3 + (4I
I15/2 ) was also measured, and the decay time was given. It’s shown that LaLu1-x Erx O3 is a potential infrared laser material, which has application value.