Transparent ceramic Ce 0.5% doped Lu3Al5O 12 (LuAG) scintillator grown by the sintering method and single crystalline Ce 0.25% doped LuAG grown by the Czochralski method are prepared. They are cut to the physical dimensions 4 4 2 mm3. Their transmittance and radio luminescence spectra are evaluated. They are both transmissive in wavelength longer than 500 nm and intense Ce3 5d-4f emission appears around 520 nm. When 137Cs -ray is irradieted, 662 keV photo-absorption peaks are clearly observed in each sample. The transparent ceramic one shows higher light yield than that of the single crystalline one. The absolute light yield of the ceramic sample is turned out to be 16000 1600 ph/MeV. The decay time constants are evaluated under pulse X-ray excitation. The main component of the decay time of ceramic and single crystalline one are determined as 37 and 46 ns, respectively.