BACKGROUND:The mechanism of differentiation and proliferation of bone marrow-derived mesenchymal stem cells remains unclear. In addition, issues such as how signal pathways such as Ca2+and bone marrow-derived mesenchymal stem cellproliferation and differentiation signals form complex signal network remain poorly understood. OBJECTIVE:To investigate the effect of Ca2+in the induced differentiation of bone marrow-derived mesenchymal stem cells into hepatocytes. METHODS:Bone marrow-derived mesenchymal stem cells were isolated from rat bone marrow using whone bone marrow adherence method, purified, amplified, and induced with hepatocyte growth factor. [Ca2+]i in the directional differentiated bone marrow-derived mesenchymal stem cells and control bone marrow-derived mesenchymal stem cells were detected with flow cytometry. Bone marrow-derived mesenchymal stem cells induced with hepatocyte growth factor were mixed with nimodipine of different concentration, and cells were divided into three groups:hepatocyte growth factor+nimodipine 10 mg/L, 50 or 100 mg/L groups. cellgrowth was observed with inverted phase contrast microscope and alpha 1-antitrypsin expression of the cells was confirmed by immunocytochemistry. The calcineurin M and the activation of extracellular signal regulated kinase pathway was detected by reverse transcription-PCR and western blotting, respectively. RESULTS AND CONCLUSION:[Ca2+]i in the directional differentiated bone marrow-derived mesenchymal stem cells was higher than in the control group (P0.05). These findings indicate that Ca2+could participate in the differentiation of bone marrow-derived mesenchymal stem cells into hepatocytes incuded with cytokines, and also maintain the survival and proliferation of bone marrow-derived mesenchymal stem cells.