Nanoparticles of strontium aluminate phosphors co-activated by Eu 2+ and Dy 3+ have been prepared by heating the precursors obtained from nitrate salt–ammonium acetic–urea–gel combustion process at temperature of 115002°C in a weak reductive atmosphere of thermal carbon. Transmission electron microscope (TEM) images revealed that the hollow nanoparticles of SrAl 2 O 4 :Eu 2+ ,Dy 3+ were formed below 115002°C, while the needle or rod-shaped particles were formed at 120002°C. The XRD patterns indicated that the resulted SrAl 2 O 4 :Eu 2+ ,Dy 3+ nanoparticles contained distorted monoclinic lattice. The environment of rare earth ion in SrAl 2 O 4 lattice was investigated by using Eu 3+ as ion probe, and the results indicated that there were two kinds of sites occupied by Eu 3+ , one was centro-symmetrical environment, while the other not. The luminescence and the afterglow properties of the hollow nanoparticles of SrAl 2 O 4 :Eu 2+ ,Dy 3+ were also investigated.