In this work, photoluminescence properties of the Y2O3:Eu3+ nanophosphor was enhanced by newly developed low temperature synthetic method. Distinguished from conventional method using high temperature of 1200degC, the synthetic temperature of the newly developed method can be lowered to 500degC by excluding chloride and nitric acid elements. Therefore, smaller sized nanoparticle could be achieved by lowering the temperature. The nanophosphor showed smaller particle size of 8 nm, and crystal structure of the smaller sized Y2O3:Eu3+ nanophosphor is mainly cubic crystal with orientation of (222), (440), and (400). In addition, the smaller sized Y2O3-10wt%Eu3+ nanophosphor synthesized by the low temperature method showed higher degree of crystallization of 11.6 of I(222/I(5M) ratio. Also, the Y2O3-10wt%Eu3+ nanophosphor showed excellent photoluminescence properties. That is, excitation wavelength was found at 250 nm, and it was the shortest one. As well, the most intensive photoluminescence emission peak could be achieved at 611 nm by using the excitation with shortest wavelength. So, photoluminescence properties could be enhanced by the newly developed low temperature synthetic method.