Tb3+ doped SrAl2O4：Eu2+，Dy3+ phosphor has been synthesized. Tb3+ doped into the phosphor as an impurity does not change the main crystalline structure and the emission spectrum, but improves the light intensity and the light – lasting time and makes the phosphor possess a longer persistent afterglow characteristic with hyperbola type decay (the radiant intensity t -1.1). The explanation of the luminescent mechanism of Tb3+ doped SrAl2O4：Eu2+，Dy3+ was presented. （From : No 2, 2006 Glass & Enamel )