With the rapid demand of white light emitting diodes (w-LEDs), studies on the ultraviolet/near-ultraviolet (UV/NUV) light excited phosphors are becoming more and more important. Herein the novel Na3GdP2O8: Re3+ (Re = Sm, Dy) phosphors were synthesized through a high-temperature solid-state reaction method. The Sm3+-doped Na3GdP2O8 phosphors emitted orange-red light centered at 600 nm, under the NUV excitation at 403 nm. When excited at 350 nm, the Na3GdP2O8: Dy3+ phosphors presented a white light emission, including three peaks at 483, 578, and 670 nm, respectively. In addition, both of the Na3GdP2O8: Sm3+ and Na3GdP2O8: Dy3+ phosphors showed excellent thermal stability at different temperatures, of which the emission intensities at 150 degrees C could maintain about 75% and 79% of those at room temperature, respectively. These results indicate that the as-prepared phosphors can be considered as potential candidates for applications in UV/NUV excited wLEDs.