Nano-Y2O3:Eu3+ was synthesized with oxalic acid as precipitate agent while adding little surfactant controlling the condition of the reaction. We obtained nanoscale powder. The particle diameter was 15-19 nm. The agglomerate size was less 1.0 micron. Compared with the ordinary powder of Y2O3:Eu3+, the peak of emission spectrum of nano-Y2O3:Eu3+ is at lambda em = 612 nm under 254 nm excitation, blue-shift 6 nm. Excitation spectrum has no difference. The phosphor was measured by PMS-3 chromatic detector and its luminescent chromatic coordinate parameters were x = 0.6479, y = 0.3442. The quenching concentration increases from micro-Y2O3:Eu3+'s 6% to 9% and the intensity of luminescence increases with the grain size growing.