Large size (φ75 mm) high quality Nd∶YAG crystals were grown by the temperature gradient technique(TGT). The carbon atoms were eliminated after O2 annealing. We have studied the core distribution and growth stripes by Zygo interferometer and orthogonal polarization microscope. The absorption spectra of Nd∶YAG crystal at room temperature have been measured. The distribution of Nd ions in Nd∶YAG crystal were studied by using absorption spectra. A comparison of temperature gradient technique and Czochralski (Cz) grown Nd∶YAG crystals was made.