Abstract: [Abstract] Objective: To investigate the effects of histone demethylase Jumonji D3 (Jmjd3) on the senescence of rat BMSCs from different embryonic origins. Methods: BMSCs were extracted from mandibular (M) and tibia (T) of rats and cultured for the following experiments. The characteristics of cell senescence were detected byβ-gal staining, and osteogenic differentiation were detected by alizarin red staining. The expression of Jmjd3 and senescence related factors, P16 and P21, were detected in M and T group by qRT-PCR and Western Blot. Then, shJmjd3 Lentivirus was constructed and transfected into T-BMSCs to knock down Jmjd3 expression. A critical-sized bone defect model was established in the rat jaw region and shJmjd3-modified BMSCs were transplanted into the defect area. The bone healing region by BMSCs transplantation was detected by Micro-CT and Masson staining. Results: SA-β-gal staining revealed that the number of senescent cells in T-BMSCs was significantly higher than that of M-BMSCs, as well as the expression of Jmjd3 and senescence related factors. T-BMSCs transfected with shJmjd3 resulted in decreased SA-β-gal positive staining cells and declined expression of Jmjd3 and senescence factors. Compared with GFP T-BMSCs, rats transplanted with shJmjd3 T-BMSCs exhibited the increased mean bone density and bone volume fraction by Micro-CT, as well as elevated trabecular bone structure by Masson staining. Conclusions: M-BMSCs exhibited lower senescence characteristics than that of T-BMSCs, which have a higher Jmjd3 expression. Inhibition of Jmjd3 in BMSCs can enhance the anti-senescence ability of cells and promote bone repair in vivo.