Abstract: Objective To investigate the role of BCL6 co-repressor, BCOR, on the myogenic differentiation potential of stem cells from apical papilla (SCAPs). Methods Retroviral full length HA-BCOR was used to over-express the BCOR in SCAPs; Western Blot was used to detect the expression of HA-BCOR; Recombinant human TGF-β1 protein was used to stimulate the myogenic differentiation in SCAPs; Real-time RT-PCR was used to detect the expressions of myogenesis related genes, Smoothened (SMO), actin, alpha 2, smooth muscle, aorta (ACTA2) and Caldeson (CALD1) to investigate myogenic differentiation capacity of SCAPs in vitro. Results Western Blot result showed that HA-BCOR could over-express in SCAPs; Over-expression of BCOR inhibited the expressions of SMO and CALD1 in SCAPs. Conclusion Our results indicated that over-expression of BCOR inhibited myogenic differentiation potential of SCAPs and BCOR was inhibitor for the myogenic differentiation in SCAPs.