Large crystals of GdYCOB (Gd_XY_<1-X>Ca_4O(BO_3)_3)(0.20<x<0.35), have been grown by the Czochralski method. Crystal growth condition was optimized. Typical size of crystals is 40mm in diameter and 50mm in length. Suitable rate of crystal rotation made the interface of crystal growth flat and reduced optically inhomogeneous core.
