A new blue-emitting phosphor based on calcium strontium phosphate host matrix, Ca2Sr(PO4)(2):Eu2+, was prepared by solid state reaction. The X-ray powder diffraction, photoluminescence excitation and emission spectra, and decay curves were measured. The phosphor emits bright blue luminescence under the excitation of near ultraviolet light. The natures of the Eu2+ emission, e. g., the Stokes shift, the chromaticity, the luminescence quenching temperature (T-0.5) were reported. It is identified that the dipole-dipole interaction plays a major role in the mechanism of concentration quenching of Eu2+ in Ca2Sr(PO4)(2):Eu2+ phosphor. The thermal activation energy for luminescence quenching in Ca2Sr(PO4)(2):Eu2+ was obtained from the temperature dependent luminescence intensities and decay curves. The phosphor Ca2Sr(PO4)(2):Eu2+ exhibits high thermal stability luminescence. (C) 2011 The Electrochemical Society. [DOI: 10.1149/1.3604743] All rights reserved.