The pure phase red phosphor yttrium borate doped with Eu3+ was prepared by a new solid state reaction named high temperature ball milling method. The phosphor was characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and luminescence spectra. The results show that the single phase YBO3:Eu3+ phosphor was obtained at 600°C, which is obviously decreased in contrast to conventional solid state reaction method. The particles are approximately nanometer size with narrow distribution range and spherical morphology. In emission spectra, the strongest peak at 597nm is due to the transition 5D0→7F1 of Eu3+ ions under 394nm monitoring wavelength. The luminescent properties of YBO3:Eu3+ phosphor with 25 mol% doping concentration of Eu3+ is optimal.