This paper reports the detailed preparation process and afterglow properties of Eu3+ activated long lasting Gd2O2S phosphor by hydrothermal routine. Rod-like Gd(OH)(3) were firstly synthesized by hydrothermal method to serve as the precursor. Long lasting Gd2O2S:Eu3+,Ti4+,Mg2+ phosphor was obtained by calcinating the precursor with co-activators and S powder. It was found from the results that the hydrothermally prepared Gd(OH)(3) revealed a rod-like morphology, while the calcinated Gd2O2S:Eu3+,Ti4+,Mg2+ phosphor showed a round granular shape. The morphological change can be explained by the etching effect of the melt that was formed by the carbonate and S powder during the high temperature calcination. The obtained Gd2O2S:Eu3+,Ti4+,Mg2+ phosphor produced a red emission upon 243 nm UV excitation, which is a typical emission of Eu3+ from D-5(j) to F-7(j) states. Long lasting behavior was observed after the UV source was switched off, due to the formation of electron traps with suitable trap depth within the matrix by the codoped Ti4+ and Mg2+ ions. (C) 2007 Elsevier B.V. All rights reserved.