We investigate the ultraviolet (UV)-light-induced transient photorefractivity in a highly Mg-doped LiNbO3 crystal. The thermal activation energy of the UV-light-induced defect centers responsible for the induced transient photorefractivity was measured to be 0.65 eV and holes were found to be the major charge carriers. These results provide a solid basis for the model that intermediate states O- are the UV-light-induced defect centers in the crystal. We also demonstrate quasinondestructive two-color holography using UV-light-induced transient photorefractivity. The two-color recording sensitivity was measured to be as high as 0.05 cm/J with a recording intensity of 5 W/cm2 at 780 nm and a gating intensity of 0.47 W/cm2 at 365 nm. © 2003 American Institute of Physics.