For enhancing the emission intensity and broadening the excitation region of Ba₃Eu(PO₄)₃(BEP), Sm³⁺is doped as sensitizer in this paper. BEP:Sm³⁺can produce an obvious red emission at near ultraviolet (n-UV) radiation. An effective energy transfer from Sm³⁺to Eu³⁺is proved. The commission international de I’Eclairage (CIE) chromaticity coordinates of BEP:Sm³⁺locate at red region. When the environment temperature is 150 °C, the emission intensity of BEP:0.10Sm³⁺is decreased to 76% of the initial one at room temperature, and the activation energy is calculated to be 0.164 eV, which can prove the good thermal stability of BEP:Sm³⁺. The results indicate that BEP:Sm³⁺may have potential applications in white light emitting diodes (LEDs).