Objective:To determine the effects of bone marrow mesenchymal stem cells on mice with endotoxemia. Methods:Mice were divided into the following groups:the control group,the endotoxemia group(the LPS group),the mesenchymal stem cell treatment group (the LPS+MSCs group) and the mesenchymal stem cell group (the MSCs group). The cardiac function of mice was respectively observed at 24 hours and day 7 after LPS administration. ELISA was performed to detect the level of cytokines in the serum,and histological examinations were performed to detect morphological changes of the cardiac muscle,liver,lung and kidney. Results:Compared to the control group,serum IL-1-茁 and TNF-α were increased in the mice of the LPS group,and MSCs treatment decreased serum IL-1-茁 and TNF-α obviously. The cardiac function of the LPS group mice deteriorated,which was rescued by MSCs treatment. Apoptosis of cardiomyocytes and hepatocytes in the mice of the LPS group was increased. Edema was observed in the pulmonary interstitium and alveolus,and ameliorated by MSCs treatment. Conclusion:MSCs inhibit the inflammatory reaction of mice with endotoxemia,improves the cardiac function and reduces the damage of the heart,liver and lung.