A series of Ca10 K (PO4) 7: Eu2+, Mn2+ (CKP: Eu2+, Mn2+) phosphors was synthesized by solid-state reaction. Under an optimal excitation of 347 nm, we have observed a blue emission band at 467 nm and a red emission band at 634 nm, which resulted from Eu2+ and Mn2+, respectively. The energy transfer from Eu2+ to Mn2+ in CKP host matrix is of a resonant type via a dipole-quadrupole mechanism. By properly varying the ratio of Eu/Mn, the emission hue can be tuned from blue (0.18,0.21), to white (0.30,0.24), and finally to red (0.35,0.24). The intensity of composition-optimized CKP: Eu2+ is about 30% of BaMg A110 O17: Eu2+. The measurement of thermal quenching for CKP: Eu2+, Mn2+ and yttrium aluminum garnet: Ce3+ was also compared and investigated in the study. The (CKP: Eu2+, Mn2+) phosphor may serve as a candidate for UV light-emitting diode application.