Objective To study the effects of serum of the Zhuartgguqiang jin tablets on the proliferation and osteogenic differentiation of bone marrow stromal stem cells (BMSCs) of aged rats.Methods The BMSCs were obtained from male SD rats of 18 months.The cell surface markers CD34,CD31,CD29 were detected by flow cytometry.The proliferation of BMSCs treated by different concentration of medicated serum (2.5%,5%,10%) at 24,48,72hours was detected by CCK-8 method.The BMSCs were divided into 4 groups,which were osteogenic induction group,the Chinese medicated osteogenic induction group,Chinese medicine group,the blank group.After the BMSCs were cultured for 7 days,alkaline phosphatase (ALP) vitality was detected.After the BMSCs were cultured for 14 days,the BMSCs were stained by alizarin red,the mRNA of ALP and osteocalcin(OC) was detected.Results The expressionof CD29 was positive,and the expression of CD31 and CD34 were negative.2.5%,5% of the medicated serum could promote cell proliferation.The ALP vitality of osteogenic induction group[202.76 ± 15.44(U/gprot)],the Chinese medicated osteogenic induction group [240.48 ± 18.55 (U/gprot)],Chinese medicine group [178.87 ± 17.29 (U/gprot)]were significantly higher than that of blank group [111.24 ± 20.71 (U/gprot)] (t =22.50,7.985,3.535,all P <0.01).The ALP activity of Chinese medicated osteogenic induction group was higher than that of osteogenic induction group (t =3.103,P < 0.05).The ALP gene relative OD value of osteogenic induction group (0.40 ± 0.20) and Chinese medicated osteogenic induction group (0.60 ± 0.06) were higher than the blank group (0.09 ± 0.03) (t =2.372,9.547,all P <0.01).The ALP gene expression of Chinese medicated osteogenic induction group was obviously higher than that of the osteogenic induction group(P <0.05).The OC gene relative OD value of osteogenic induction group(0.58 ± 0.09) and Chinese medicated osteogenic induction group(0.76 ± 0.11) were higher than the blank group(0.41 ± 0.02) (P < 0.05,P < 0.01).The OC gene expression of Chinese medicated osteogenic inductiongroup was obviously higher than that of the osteogenic induction group(t =2.673,P < 0.05).Conclusion Medicated serum of Zhuangguqiangjin tablets can promote the proliferation and osteogenic differentiation of BMSCs of aged rats,which may be the mechanism of prevention senile osteoporosis. Key words: Chinese medicine; Bone marrow stromal stem cells; Osteoblasts; Cell differentiation