To investigate the feasibility of using chitin, a natural polymer, as a scaffold to repair large growth plate defects (50% of physis) in immature rabbits, mesenchymal stem cells (MSCs) were harvested from periosteum. The compatibilities of chitin with the MSCs were investigated in vitro using immunohistochemistry and fluorescence confocal microscopy. The results showed high compatibilities of chitin. An experimental model of growth arrest was created by excising the medial half of the proximal growth plate of the tibia in 6-week-old New Zealand White rabbits. The physeal defect after excision of the bony bridge was transplanted either with no interposition (group 1), chitin alone (group 2), or chitin with MSCs (group 3). In groups 2 and 3, both angulatory deformities and length discrepancies of the tibia were corrected. The differences between group 3 and group 1 were greater than those between group 2 and group 1.