Polycrystalline Nd3+ and La3+ co-doped yttria nanopowder Nd3+:Y1.90La0.10O3 for transparent ceramics was synthesized by co- precipitation method using oxalate acid as the precipitant and (NH4)2SO4 as the electrical stabilizer under ultrasonic radiation.Nanopowders calcined at different temperatures were characterized with thermal gravimetric-differential thermal analysis (TG/DTA),X-ray diffraction (XRD),transmitting electron microscopy (TEM),energy dispersive spectrometry (EDS) and spectral analysis techniques.The results indicated that nanopowders calcined at 1100℃ for 4 h were 40-70 nm in size with spherical morphology,the powder had the strongest emission peak centered at 1078 nm,corresponding to the transition of 4F3/2→4I11/2 of Nd3+ ion.The highest optical transmittance of the ceramics sintered at 1500℃ for 13 h was about 48% in near IR waveband,and the sintered ceramics had a broad absorption bandwidth of about 12.6 nm at the laser diode (LD) pump wavelength of 808 nm.