The influence of surface orientation and the off-cut direction of substrates on micropipe dissociation have been investigated. Micropipe dissociation was confirmed on epilayers grown on (0001) Si- and (000-1) C-face substrates with the off-cut directions towards <11-20> and <1-100>. The line-shaped surface depressions on micropipes were visible and micropipe dissociation confirmed at a lower C/Si ratio (< C/Si = similar to0.85) on the Si-face. On the other hand, the line-shaped depressions on micropipes were observed on epilayers grown at C/Si ratios of 0.4, 0.55, 0.7 and 0.85 on the C-face. Micropipe dissociation was also found on the C-face in a C/Si ratio range from 0.4 to at least 0.85.