Transparent polycrystalline α-Al2O3 ceramics were fabricated by conventional solid-state processing with MgO as additive. The absorption, excitation, emission spectra and thermoluminescence of α-Al2O3 transparent ceramics were investigated. There are two characteristic absorptions, one is centered at 192 nm, and the other at from 230 to 250 nm, which are caused by F+ and F color centers, respectively. There is one obvious emission peak located at 410 nm. Based on the excitation spectra, it is shown that the emission peaks are caused by the absorption of F+ and F color centers. The thermoluminescence curves show three peaks centered at 368, 456 and 614 K, respectively. The peak centered at 456 K may be caused by F and F+ centers.