gamma-aluminum oxynitride (-AlON) with spinel structure has attracted much attention for structural and functional application. -AlON powders were successfully prepared by direct nitridation method of Al/Al(OH)(3) starting mixture in ammonia and then calcined at high temperature. XRD, SEM, TEM, EDX, and photoluminescence were conducted to investigate the detail procedure and the optical properties of AlON: xEu phosphors. Nitrogen was introduced by the nitridation of metallic aluminum, appropriate Al amount and nitridation condition was necessary to obtain phase pure -AlON. The as-prepared AlON powders exhibited multifaceted grain morphology with fine particle size (1-5m). Eu2O3 activator was reduced and transformed to EuAl12O19 by reaction with alumina, which remained in the product when x>0.25%. Under 331nm excitation, AlON: xEu phosphors exhibited emission bands of 475 and 410nm. 475nm band reached a plateau at x=0.25% due to the solubility of Eu2+ ion in AlON, whereas 410nm band showed a linear increase in intensity with Eu2+ doping amount, which was believed to be the contribution of EuAl12O19. The present approach combination of direct nitridation in ammonia and postcalcination process showed potential application for AlON ceramic and AlON phosphors.