This paper reports the detailed preparation process of Eu 2+ activated long lasting Sr 4Al 14O 25 nano sized phosphor by precipitation method. Scanning electron microscopy (SEM), simultaneous DSC–TG, X-ray diffraction (XRD), photo luminescent spectroscope (PLS) and thermal luminescent (TL) spectroscope were employed to characterize the phosphor. SrAl 2O 4:Eu 2+Dy 3+ and Sr 4Al 14O 25:Eu 2+Dy 3+ phosphors in nano scale were obtained by calcinating the precipitated precursor at 1200 and 1300 °C, respectively. Both the low-temperature product SrAl 2O 4:Eu 2+Dy 3+ and the high-temperature product Sr 4Al 14O 25:Eu 2+Dy 3+ showed photoluminescence upon UV illumination with an emission peak at 480 and 505 nm, respectively. When compared to the powder obtained in conventional method, the nano sized powders revealed a blue shift in emission spectrum due to the decrease in grain size. Those two phosphors showed long persistent afterglow, and the Sr 4Al 14O 25:Eu 2+Dy 3+ phosphor exhibited better afterglow property than SrAl 2O 4:Eu 2+Dy 3+ phosphor due to a deeper trap level and a higher trap concentration formed in the host material.