Abstract: Objective：To investigate the effect of BCOR-short on the osteogenic differentiation potential of stem cells from apical papilla (SCAPs). Methods：Retroviral HA-BCOR-short was used to over-express the BCOR-short in SCAPs. Western Blot was used to detect the expression of HA-BCOR-short. Alkaline phosphatase (ALP) activity assay was used to detect the early marker of osteogenic differentiation-ALP activity, Alizarin-red staining and quantitative analysis of calcium were used to investigate the mineralization potential of SCAPs in vitro. Real time RT-PCR was used to detect the osteogenesis related genes expressions bone sialoprotein (BSP), osteocalcin (OCN) and AP2A. Results：Western Blot result showed that HA-BCOR-short could over-express in SCAPs. The over-expression of HA-BCOR-short inhibited ALP activity, mineralization, and the expressions of BSP and OCN in SCAPs. The AP2A expression was repressed in HA-BCOR-short over-expressed SCAPs compared with control group. Conclusions：Our results indicated that over-expression of HA-BCOR-short repressed osteogenic differentiation potential of SCAPs and the expression of AP2A.