The fabrication of 0.5mol% Ce:LuAG transparent ceramics starting from synthetic nanosized Ce:LuAG powders was investigated by low temperature vacuum sintering. It was found that high quality optical Ce:LuAG ceramics could be densified successfully by vacuum sintering (<10-3 pa) at 1750 degrees C for 10h. The in-line optical transmittance of as-sintered Ce:LuAG ceramics with thickness of 0.7mm could reach 73.48% at the wavelength of 550nm. The microstructure observations revealed that transparent Ce:LuAG ceramics were composed of uniform LuAG grains with average size of 9m and HRTEM morphology indicated that no impurity segregation existed at grain boundaries or within Ce:LuAG grains. It was also demonstrated that the annealing treatment (at 1450 degrees C for 20h in air) could greatly enhance the luminescent intensity of as-sintered Ce:LuAG ceramics under excitation of X-ray radiation (75kV, 25mA), which makes it a potential candidate to be applied in radiation detector.