SrZn₂(PO₄)₂:Sm³⁺phosphor was synthesized by a high temperature solid-state reaction in atmosphere. SrZn₂(PO₄)₂:Sm³⁺phosphor is efficiently excited by ultraviolet (UV) and blue light, and the emission peaks are assigned to the transitions of ⁴G_5/2-⁶H_5/2(563 nm), ⁴G_5/2-⁶H_7/2(597 nm and 605 nm) and ⁴G_5/2-^{6H_9/2(644 nm and 653 nm). The emission intensities of SrZn₂(PO₄)₂:Sm3+are influenced by Sm3+concentration, and the concentration quenching effect of SrZn₂(PO₄)₂:Sm3+is also observed. When doping A+(A=Li, Na and K) ions, the emission intensity of SrZn₂(PO₄)₂:Sm3+can be obviously enhanced. The Commission Internationale de l'Eclairage (CIE) color coordinates of SrZn₂(PO₄)₂:Sm3+locate in the orange-red region. The results indicate that the phosphor has a potential application in white light emitting diodes (LEDs).}