OBJECTIVE: To investigate the effects of traditional Chinese medicine on the differentiation of mesenchymal stem cells (MSC) to osteoblasts. METHODS: Six male Beagle dogs weighed 10-15 kg each were divided into three groups, group A: medicine serum group, group B: non-medicine serum group and group C: bovine serum group. The serum of group A was obtained from the femoral artery of 2 Beagle dogs drinking equivalent dose of traditional Chinese medicine according to body surface area for 7 continuous days. The serum of group B was collected from the femoral artery of 2 Beagle dogs fed with equal volume of normal saline for 7 days. The serum of group C was fetal bovine serum. The tibia marrow was harvested from another 2 Beagle dogs and MSC were isolated and purified by density gradient centrifugation. MSC were cultured in DMEM solution with fetal bovine serum. After MSC were digested by trypsin, MSC were cultured in DMEM solution with the osteogeneic inducer, which contained dexamethasone, antiscorbutic and beta-glycerophosphate. Morphological and histological changes of the MSC were observed under an inverted microscope. Alizarin monosulfonate and nitric acid argentum staining was performed to observe the calcium deposition. MSC were curtured in DMED solution with medicine serum (group A), non-medicine serum (group B) and bovine serum (group C) respectively. The growth curve was detected by the methyl thiazolyl tetrazolium (MTT). The alkaline phosphatase (ALP) activities were detected to observe the differentiation of MSC. RESULTS: The original MSC were observed as fibroblast-like cell shapes. After the osteogeneic inducer was added, MSC were polygon cells with a few polyprocess. Calcium deposition appeared during 10-14 days and alizarin monosulfonate and Von Kossa staining presented positive. MTT results showed that the number of adherent cells of group A was more than that of group B and that of group C significantly after 6 days (P < 0.05). ALP detection proved that ALP activity of group A was more than that of group B and that of group C significantly after 5 days (P < 0.05). CONCLUSIONS: The traditional Chinese medicine promotes the differentiation of MSC to osteoblasts and osteogenesis.