Abstract: In this research, the effect of light excitation conditions on the afterglow and thermoluminescent performance of luminescent polyester fiber have been studied. The afterglow decay laws and thermoluminescent characteristics of the fiber were measured by afterglow tester and TL dosimeter. The results indicated that light excitation conditions had impacts on the initial intensity and decay time of the fiber, which had not showed linear change yet. The higher the excitation intensity is, the faster the decay speed is and the shorter the decay time attaining to the same luminescent illumination is. Increasing the excitation time did not prolong the decay time of materials. The light excitation conditions did not change the trap level depth of SrAl204：Eu2+，Dy3, but increase the electronic concentration of the trap level obviously.The greater the excitation intensity and the longer the excitation time are, the higher the relative intensity of thermoluminescent peak is.

Key words: luminous polyester fiber, excitation conditions, afterglow decay, thermoluminescence