Abstract: Objective To investigate the effect of ginsenoside Rg3 on the maturation and function ofhuman peripheral blood monocyte-derived dendritic cells(DC). Methods ①The differentiation of peripheral blood mononuclear cells(PBMC) to immature DC(imDC) was induced by the combination of GM-CSF and IL-4.On the fifth day,TNF-α was added to make the mature of DC,so as different doses of Rg3,which were divided into low dose group(10 μg/ml),middle dose group(20 μg/ml),high dose group(40 μg/ml) and control group.The expression of CD80,CD86 and CD83 on DC cell surface which induced by Rg3 at the 7th and 14th day were detected byflow cytometry.②Rg3-DCs were collected at the 7th and 14th day,then mixed lymphocyte reaction was performed,MTT method was used to analyze the influence of ginsenoside Rg3 and DCs on the stimulation of allogeneic lymphocyte proliferation;③The interleukin-12(IL-12) level produced by Rg3-DCs were detected with ELISA. Results ①The expression of DC markers CD80,CD86 and CD83 on cell surface of middle and high Rg3 dose groups were significantly increased after culture for 7 and 14 days,the difference was significant as compared with the control group(P＜0.05).The mature markers of CD83 at the 14th day of middle and high dose groups were (38.60±2.21)% and (44.21±4.94)%,respectively,which was significantly higher than that of the control group (28.45±7.20)%,P＜0.05 and P＜0.01.①Rg3-DCs showed more effective in the high dose group on stimulating lymphocyte proliferation when compared with the other groups(P＜0.05).③In the high dose group,IL-12 level produced by Rg3-DC was (34.45±4.42)pg/ml,which was higher than that of the control group (10.24±8.82)pg/ml,P＜0.05. Conclusion Ginsenoside Rg3 can induce DC maturation,promote thefunctional conversion.A dose-dependent can be observed within a certain concentration.