Abstract: OBJECTIVE To observe the protective effects of astragaloside on inflammatory injury induced by oxidative low density lipoprotein (ox-LDL) in endothelial progenitor cells( EPCs), and find the potential mechanisms. METHODS Total mononuclear cells(MNCs) were isolated from peripheral blood of healthy young human volunteers by ficoll density gradient centrifugation, and plated on fibronectin-coated culture dishes. After incubation for 7 days, attached cells will be collected and randomized into five groups: control group, ox-LDL-intervented group, and three astragaloside-intervented groups which were respectively added with different concentrations of astragaloside (2, 10 and 50 μg·mL^-1) and 100 μg·mL^-1 ox-LDL. After intervention for 24 hours, the capacities for EPCs vasculogenesis, migration, adherence, as well as proliferation separatively were evaluated and the levels of IL-6 and TNF-α in the culture supernate of the five groups were measured. RESULTS Compared with the control group, the capacities for EPCs vasculogenesis, migration, adherence, as well as proliferation were impaired and the levels of IL-6 and TNF-α were obviously elevated in the ox-LDL-intervented group (P<0.01). In contrast, these capacities as well as IL-6 and TNF-α levels were improved in astragaloside-intervented groups. CONCLUSION Astragaloside can protect the EPCs capacities of vasculogenesis, migration, adherence, and proliferation which would be injured by ox-LDL. The potential mechanism might be related to its anti-inflammatory features.