A blue phosphor based on phosphate host matrix, SrMg2(PO4)(2): Eu2+, was prepared by solid state reaction. The phosphor emits bright blue luminescence with a peak wavelength at 423 nm under ultraviolet excitation at 363 nm. Based on the experimental results and the theoretical calculation, it is identified that the dipole-dipole interaction plays a major role in the mechanism of concentration quenching of Eu2+ in SrMg2(PO4)(2): Eu2+ phosphor. In addition, the obtained phosphor SrMg2( PO4)(2): Eu2+ exhibits higher thermal stability than commercially available YAG: Ce3+ phosphor, especially above 390 K. (C) 2008 Elsevier B. V. All rights reserved.