Eu2 +,Dy3 + co-doped strontium aluminate (SrAl2O4) phosphor nanoparticles with high brightness and long afterglow were prepared by glycine-nitrate solution combustion synthesis at 500℃, followed by heating the resultant combustion ash at 1100℃ in a weak reductive atmosphere of active carbon. The average particle size of the SrAl2O4:Eu,Dy phosphor nanoparticles ranges from 15 to 45nm as indicated by transmission electron microscopy (TEM). The broad-band UV-excited luminescence of the SrAl2O4:Eu,Dy phosphor nanoparticles was observed at kmax=513nm due to transitions from the 4f65d1 to the 4f7 configuration of the Eu2+ion. The results indicated that the main peaks in the emission and excitation spectrum of phosphor nanoparticles shifted to the short wavelength compared with the phosphor obtained by the solid-state reaction synthesis method. The decay speed of the afterglow for phosphor nanoparticles was faster than that obtained by the solid-state reaction method.