Tervalent cerium ions (Ce3+)-doped oxonitridosilicate compound Y2Si3O3N4 were prepared by solid-state reaction method in a reduced atmosphere. The products were characterized by X-ray diffraction (XRD), diffuse reflection, scanning electron microscope (SEM), photoluminescence (PL) and photoluminescence excitation (PLE) measurements. The effects of Ce3+ doping concentrations and NH4Cl flux on structural and luminescent properties of the Y2Si3O3N4 phosphors were investigated in detail. The phosphors showed intense absorption in near ultraviolet (NUV) region and exhibited bright blue emission with tunable Commission Internationale de l'Eclairage (CIE) coordinates of (0.199, 0.334) to (0.177, 0.248) under 397 nm excitation. Evidence demonstrates that the phosphors were promising blue-emitting phosphors candidates for white LEDs for general illumination or displays. (C) 2011 The Electrochemical Society. [DOI: 10.1149/2.002203jes] All rights reserved.