Effects of graphitization degree of the crucible on the crystal growth conditions, such as temperature distribution and growth rate, were investigated by simulations. It was found that graphitization degree of the crucible increased when the crucible was repeatedly used for a long time. Power consumed by the crucible rose, whereas the total power consumed by both crucible and insulation decreased with the graphitization degree increasing. When keeping seed temperature constant, the source powder temperature and axial temperature difference between source powder and crystal seed decreased, which resulted in lower growth rate. Simulations were in good consistence with experiment results. Some clues to growth reproducibility were given. (C) 2008 Elsevier B.V. All rights reserved.