【Abstract】 Objective To investigate the effect of allogeneic bone marrow-derived mesenchymal stem cells ( BMSCs) transplantation on the airway inflammation and airway remodeling in chronic asthmatic mice. Methods Forty female BALB/c mice were equally randomized into four groups, ie. a normal control group, a BMSCs control group, an asthma model group, and a BMSCs transplantation group. BMSCs were generated from male donor mice, then the mice in the asthma model group and the BMSCs transplantation group were sensitized and challenged with OVA to establish chronic asthmatic mice model. Hematoxylin and eosin staining and Alcian blue-periodic acid-Schiff staining were used to analyze the effects on airway inflammation and airway remodeling after BMSC engraftment. The number of CD4 + CD25 + regulatory T cells in spleen was detected by flow cytometry. Results In lungs of the asthmamodel group, there were intensive inflammatory cells infiltration around airway and blood vessels, goblet cell proliferation, epithelial desquamation, patchy airway occlusion by hyperviscous mucus, and hypertrophy of airway smooth muscle.Airway inflammation and airway remodeling were significantly relieved in the BMSCs transplantation group.There was no obvious inflammatory cells infiltration in the airway and airway remodeling both in the normal control group and the BMSCs control group. The number of CD4 + CD25 + regulatory T cells in spleensignificantly decreased in the asthma model group compared with the two control groups ( P lt; 0. 05) , and significantly increased in the BMSCs transplantation group compared with the asthma model group ( P lt;0. 05) . There was no significant difference in the number of CD4 + CD25 + regulatory T cells in spleen betweenthe control groups and the BMSCs transplantation group. Conclusion BMSCs engraftment can up-regulate CD4 + CD25 + regulatory T cells and relieve airway inflammation and airway remodeling in asthmatic mice.