Ce:Y3Al5O12 transparent ceramics are fabricated by solid state reaction method through vacuum sintering. The in line transmittance in visible light region is higher than 80% . Different doping concentrations (atomic fraction of 0.1%, 0.3%, 0.5%, 1.0%) and thicknesses (0.5, 1.0, 2.0 mm) are investigated by considering their luninous efficiencies, color rendering index and color temperatures. After being packaged with GaN chip using commercil resin, the prime luninous efficiency reaches to 131.5 lm/W. It is proved that Ce:Y3Al5O12 transparent ceramics will be a promising phosphor prior to powder phophors in white LED devices.