A series of Ce3+, Tb3+ codoped and Ce3+, Tb3+, Eu3+ tridoped KBaY(BO3)(2) (KBYB) phosphors are synthesized by the solid-state method. The codoped and tridoped phosphors absorb near-ultraviolet (NUV) light through 4f-5d transitions of Ce3+, followed by blue emissions of Ce3+ along with sensitized Tb(3+)green and Eu(3+)red emission, respectively. The energy-transfer process is discussed in terms of both the luminescence spectra and decay curves. Because of the long Y-Y distance in KBYB structure, high Tb3+ content is required to form a Tb3+ bridge for a complete Ce3+ -> Tb3+ -> Eu3+ energy transfer. By controlling the Ce3+/Tb3+/Eu3+ ratio, the color of the phosphor varied from blue (0.173, 0.087) to green (0.341, 0.570) and eventually to red (0.589, 0.374). The results indicated that the codoped and tridoped KBYB exhibited broadband NUV absorption and blue-green-red tunable emission, which might serve as down-converted phosphors for NUV light-emitting diodes.