The highpurity and singlephase terbium gallium garnet (Tb3Ga5O12,TGG) polycrystal was synthesized by the raw materials of 99.99% Ga2O3 and Tb4O7 in stoichiometric weights with proper excess of Ga through the solid phase reaction method (the segmentation warmingup technology). An integral, crackfree, spiralfree TGG single crystal with size of 44mm×70mm was grown successfully by Czochralski(CZ) method. The TGG polycrystal and asgrown crystals were characterized by Xray diffraction spectroscopy, density and composition analysis. XRD analysis. The results indicate that the asgrown crystal is integrated in structure and crystallized well. The density of TGG single crystal is 7.14 g/cm3, very closed to the theoretical value. The composition analysis result shows that the ratio of Tb to Ga is 66%, that indicates that there exists a small amount of vacant of Ga.