Silicon carbide bulk crystals have some kinds of defects such as micropipe and planar defect. These defects can be observed using an optical microscope. As crystal grew, its diameter was expanded by the sublimation method, and planar defect density decreased, while planar defect size became small. Some micropipes were annihilated at the sidewall of planar defect. These results were caused by the change of growth mode and the movement of planar defect due to temperature gradient in a graphite crucible.