Using a self-designed temperature testing box in which Xenon-lamp irradiation can be applied, the afterglow feature of SrAl2O4:Eu,Dy as a function of temperature has been researched. Two sorts of SrAl2O4:Eu,Dy phosphors, namely highest quality commercial one and the self-synthesized one by solid-state reaction process were employed. Results reveal a common phenomenon behaving as phosphorescent sudden extinguishments at a certain low temperature although their threshold temperature value (about 223 K) has a slight difference. The general characteristic for the influence of temperature on the afterglow feature presents, compared to the luminescent decay at room temperature (RT), a bigger and faster decrease of phosphorescent brightness with the reduction of temperature, while decay curves still maitain the same patt composed of a quick decline part and a platform falling part during which the phosphorescent brightness at 273 K is only about 1/2 as big as that at RT, and at 253 K the figure has changed to about 1/3. Finally, the reason of previous observed results has been analyzed briefly in theory.