An orange-red emitting phosphor Ca₉Al(PO₄)₇:Sm³⁺ was synthesized by a high temperature solid-state method,and its luminescent properties are investigated.Phase form ation was determined by X-ray diffraction (XRD) in a Bruker AXS D8advanced automatic diffractometer (B ruker Co.,German) with Ni-filtered Cu Kα1radiation (λ=1.5406nm).Steady time resolved luminescence spectra,and excitation and emission spectra were detected by a fluorescence spec trophotometer (Hitachi F-4600).Commission International de I′Eclairage (CIE) chromaticity c oordinates of samples were measured by a PMS-80spectra analysis system.Under 403nm radiatio n excitation, Ca₉Al(PO₄)₇:Sm³⁺ has several emission peaks,and they locate at 564nm,605nm,650nm and 712nm, which are ascribed to ⁴G5/2→⁶H5/2,⁴G5/2→ 6H7/2, ⁴G5/2→⁶H9/2 and ⁴G5/2→⁶H 11/2 transitions of Sm³⁺. And the strongest emission is 605nm,so Ca₉Al(PO₄)₇:Sm³⁺ pr esents orange-red light.The emission intensities of Ca₉Al(PO₄)₇:Sm³⁺ are influenced by Sm3+ concentration,and can achieve the maximum at 0.01Sm³⁺,and the concentration quenching effect of Sm³⁺ in Ca₉Al(PO₄)₇:Sm³⁺ is observed.The mechanism of concentration quenching is the d-d interaction.CIE color coordinates of Ca₉Al(PO₄)₇:Sm³⁺ locate in the orange-red regi on,and are not influenced by Sm³⁺ concentration. Under different temperatures,the emission intensities of Ca₉Al(PO₄)₇:0.01S m³⁺ are investigated,and the corresponding activation energy is calculated to be 0.178eV,which prove th e thermal stability of Ca₉Al(PO₄)₇:Sm³⁺.