Nd，La:Y2O3 nanocrystalline powder was prepared by co-precipitation method. The transparent ceramic was fabricated by vacuum sintering at 1700℃ for 4 h in vacuum. Transparent polycrystalline ceramics with uniform lanthanum distribution was obtained. The grain size was around 22 μm. No pores were found in the grain and grain boundary. The absorption spectrum and the fluorescence spectrum of the sample were measured. The highest absorption peak is centered at 821 nm and the absorption cross section is 43×10-24 m2 The main emission peak is at 1078 nm, and the fluorescence lifetime is 0287 ms. The Judd-Ofelt intensity parameter Ωλ（λ=2，4，6）, spontaneous transition probability, radiative lifetime and fluorescence branching ratio of Nd3+ were calculated by Judd-Ofelt theory. The calculated emission cross section of 4F3/2→4I11/2 transition is 20×10-24 m2 It was found that the addition of La ion can change the crystalline field of yttria, which helps to obtain suitable solid laser materials.