Na2SO4∶Dy3+ phosphors were prepared by heating pure natural thenardite(Na2SO4) with DyF3 at 900　℃ for 25 min in air. studied the Luminescence properties of Na2SO4∶Dy3+ were studied by synchrotron radiation. Their photoluminescence (PL) spectra were also investigated under vacuum ultraviolet-ultraviolet (VUV-UV) at room temperature.According to the emission spectra, the yellow-blue ratio (Y/B) is different under different concentrations of Dy3+ and the position of excitation.And the excitation spectrum is consisted of strong bands assigned to the 4f9→4f8 5d transition at 172 nm, the O2-- Tm3+charge transfer band at 165 nm and weak bands assigned to host absorption(138, 245 nm) and the 6H15/2→4D7/2,6H15/2→6P3/2,　 and 6H15/2→6P7/2 transition at 299,　325 and　351 nm respectively.