A novel emitting color tunable phosphor Ba 3 Gd(PO 4 ) 3 : Ce 3+ , Tb 3+ was synthesized by the traditional high temperature solid state reaction method. The photoluminescence (PL) and energy transfer (ET) properties of Ce 3+ and Tb 3+ doped Ba 3 Gd(PO 4 ) 3 host were studied in detail. The obtained phosphors show both a blue emission from Ce 3+ and a yellowish-green emission from Tb 3+ with considerable intensity under ultraviolet (UV) excitation (~310nm). When the content of Ce 3+ was fixed at 0.05, the emission chromaticity coordinates could be adjusted from blue to green region by tuning the contents of Tb 3+ ions from 0.01 to 0.5 through an ET process. The critical distance between Ce 3+ and Tb 3+ is 16.16Å. The ET mechanism from Ce 3+ to Tb 3+ ions was proved to be dipole–dipole interaction. The developed phosphor exhibits a strong excitation in UV spectral region and high efficient ET from Ce 3+ to Tb 3+ ions. It may find applications as a green light-emitting UV-convertible phosphor in white LED devices. Furthermore, a white light emission phosphor Ba 3 Gd(PO 4 ) 3 : Ce 3+ , Tb 3+ , Mn 2+ was also investigated.