In the current study long afterglow phosphors in strontium aluminate system doped with Eu2+ and Dy3+ were synthesized at different firing temperatures for various time. Photoluminescency and crystallisation during sintering under reducing atmosphere were examined as functions of sintering time and temparature. XRD was employed to characterize the crystal phases of phosphors. Scanning electron microscopy (SEM) investigations were carried out to understand surface morphology and to confirm the XRD results. The optical properties of the phosphors were investigated by a phosphorescence spectrophotometer. The changes in emission and excitation spectrum were discussed accounting firing time and temperature.