Transparent polycrystalline MgO and TiO2 codoped Al2O3 ceramics were fabricated by conventional solid-state pressureless processing. The absorption, emission and excitation spectra of (Mg，Ti):Al2O3 ceramics were measured. Owing to charge compensation of Mg2+, only UV absorption around 250nm was observed due to O2-→Ti4+ charge transfer transitions (CT) when Ti content was low. As a result, the emission peaks of isolated Ti4+ ion located at 280—290nm and 410—420nm were observed. Besides absorption peak of Ti4+ ion, the characteristic absorption peak of Ti3+ ion centered at 490nm was observed in (Mg，Ti):Al2O3 ceramics when Ti content was high. The emission spectra of Ti3+ ion in polycrystalline Al2O3 ceramics coincide with that of Ti:Al2O3 single crystal.