P>Objective To study the biological characteristics of human bone mesenchymal stem cells(hBMSCs) which were expressed telomerase catalytic subunit. Methods HBMSCs cells were infected by the retroviral particles（pBabepuro- hTERT）, and then the infected hBMSCs were selected by puromycin.We named infected HBMSCs as hTERT-hBMSCs.The telomerase activity of hTERT-hBMSCs and HBMSCs were detected by TRAP (PCR)-ELISA；The life character of hTERT-hBMSCs were observed by MTT, chromatosome kayotype，the rate of colony formation and osteoblast differentiation. Results TRAP (PCR)-ELISA detected that the telomerase activity of hTERT-hBMSCs was positive. The phenotype of hTERT-hBMSCs was CD44 positive and CD34 negative.The growth speed of hTERT- hBMSCs was higher than that of hBMSCs.Presently it had propagated eleven generations, but didn’t exhibit senescent phenomenon.hTERT-hBMSCs showed that chromatosome was nomal diploid，not aberration，the rate of colony formation was lower and the differentiational osteoblast capability of stem cells were maintained.Conclusion Infected Exogenic hTERT in