Objective: Mesenchymal stem cells (MSCs) are precursors of tissue of mesenchymal origin, the use of MSCs has been successfully tested in different animal models. The study was carried-out to assess the effect of stem cell therapy on regenerating damaged intestine mucosal cells of mouses after irradiation. Methods: the mouses were irradiated with doses of 8.5 Gy by Tomotherapy machine at the Institute for Radiation Protection and Nuclear Safety in France.The regeneration and recovery of intestinal cells of the irradiated mouses not injected and injected by bone marrow mesenchymal stem cells were followed-up. Results: damaged villi of small intestine cells, died endometrial cells, formed large gaps, dilated blood vessels were found in the irradiated mouses n9t injected by stem cells.The regeneration and restoration of intestine cells and the new blood vessels formation were observeq in the irradiated mouses 3 days after injecting a dose of 10 exponent 7 cells/ml mesenchymal stem cells. Conclusion: a dose of 10 exponent 7 cells/ml bone marrow mesenchymal stem cells enhanced to regenerate and restore the damaged intestinal cells of irradiated mouses.