Abstract: The purpose of this paper was to study the effects of panaxatriol saponins (PTS) on osteoblasts，mineralization and apoptosis.MTT，p-nitropheneye phosphate，RT-PCR and Von Kossa staining was used to observe the effects of PTS on cell viability，alkaline phosphatase (ALP) activity，osteocalcin (OC) mRNA expression and mineralization of MC3T3-E1 cells.The serum deprivation-induced apoptosis of osteoblasts was determined by flow cytometry.Compared with the control group，there was no significant difference of cell viability in all experimental groups.Higher doses of of PTS could improve ALP activity obviously compared with the control group during early differentiation phase of MC3T3-E1 cells，among which 10 μg/mL of PTS had the strongest promoting effect.However，the stimulating effect of ALP activity of MC3T3-E1 cells by PTS was blockaded by estrogen receptor antagonist ICI 182780.After 21 days of treatment，higher doses of PTS could markedly increase the mRNA expression of OC.Besides，the number of mineralized nodules increased at different levels in MC3T3-E1 cells after 28-day incubation with different concentrations of PTS.1 μg/mL and 10 μg/mL PTS could significantly inhibit serum deprivation-induced apoptosis of MC3T3-E1 cells.All these suggested that PTS could effectively promote the differentiation and mineralization of osteoblasts and inhibit their apoptosis，and might act as an estrogen agonist in MC3T3-E1 cells，potentially capable of being developed as anti-osteoporosis agents.