【Objective】To establish a cell model of radiation injury of human bone marrow mesenchymal stem cells（hBMMSC），and to provide experimental basis for further study on the pathogenesis of osteoradionecrosis of the jaws（ORNJ）.【Methods】After X-ray irradiation，the gene expression change of Beclin1，Sox2，Nanog，RUNX2 and OGN in hBMMSC were evaluated by Western blot and RT-qPCR. The apoptosis rate change was detected by Annexin- V/PI double staining method. The proliferation rate change was determined by clone formation experiment. The alkaline phosphatase activity change was detected by microplate method.【Results】The gene expressions of Beclin1 increased with the doses increased，while Sox2，Nanog，RUNX2 and OGN in hBMMSC were all down- regulated after irradiation. The apoptotic rate increased，the colony formation rate decreased and the alkaline phosphatase activity decreased also.【Conclusion】X-ray irradiation can cause ionizing radiation injury of hBMMSC. We successfully established a cell model of hBMMSC radiation injury，the model can be applied to the experimental study of the pathogenesis of ORNJ.