A series of Ce3+/Mn2+-coactivated MgY4Si3O13 phosphors with oxyapatite nature have been prepared via high temperature solid state reaction process and their structural and luminescence property was thoroughly investigated. On examining the Mn2+ concentration-dependent photoluminescence properties, we found that the increment of Mn2+ concentration would lead to a systematic decrease of Ce3+ emission due to the efficient energy transfer from Ce3+ to Mn2+, which occurs because of the spectral overlap between the emission band of Ce3+ and the excitation band of Mn2+. The resonant energy transfer from Ce3+ to Mn2+ via a dipole-quadrupole mechanism was supported by decay lifetime data and the critical distance (R-C) of the energy transfer was calculated to be 14.13 angstrom. The color-tunable emission in Ce3+/Mn2+ codoped system as a function of Mn2+ concentration can be realized by continuous shifting of the emission colors from blue to white and eventually to orange red region. Based on the results in this study, MgY4Si3O13: Ce3+, Mn2+ phosphors are considered efficient phosphors with excellent color tunability for white UV-LEDs. (C) 2012 The Electrochemical Society. [DOI: 10.1149/2.077205jes]