Composite structure Y3Al5O12 transparent ceramics were prepared by an aqueous tape casting method. The slurry of Al2O3 and Y2O3 powders shows a shear thinning behavior. The powders were distributed homogeneously in the tapes. The average grain size of YAG ceramics sintered at 1750 °C for 10 h is 15 μm. The inline transmittance of the sample polished to 1.0 mm is 81.5% at the wavelength of 1064 nm.