The single-composition Ca9Y(PO4)7:Eu 2+, Mn2+ phosphors were synthesized by a solid-state reaction. The luminescent properties and electronic structures were investigated by photoluminescence (PL) and X-ray absorption near-edge structure (XANES). The PL demonstrated energy transfer and a red-shift as the Mn doping level was increased. The energy transfer is ascribed to charge transfer between Eu and Mn. The change of the PL intensity is caused by the increased O 2p-Mn 3d hybridization. The narrowing of the band gap, which finding is supported by the red-shift, is responsible for the formation of the Mn-related states close to the conduction band minimum.