Tb3+-doped and Eu2+, Tb3+ co-doped Ca9Y(PO4)(7) phosphors were synthesized by conventional solid-state method. Additionally, the luminescence properties, decay behavior and energy transfer mechanism have already been investigated in detail. The green emission intensity of Tb3+ ions under NUV excitation is weak due to its spin-forbidden f-f transition. While Eu2+ can efficiently absorb NUV light and yield broad blue emission, most of which can be absorbed by Tb3+ ions. Thus, the emission color can be easily tuned from cyan to green through the energy transfer of Eu2+Tb3+ in Ca9Y(PO4)(7):Eu2+,Tb3+ phosphor. In this work, the phenomenon of cross-relaxation between D-5(3) and D-5(4) are also mentioned. The energy transfer is confirmed to be resulted from a quadrupole-quadrupole mechanism.