Aim The effects of macrophage colony stimulatingfactor (0CSF) on the antioxidative capacity and foamcell formation of murine peritoneal macrophages wereobserved.Methods MCSF was in the conditional cultural liquidsof L929 cell line. Superoxide dismutase(SOD) activi-ty was detected by Pyroyallol method, and seleniumdependent glutathione peroxidase (SeGSHPx) activitywas detected by DTNB method, the survival numberof murine macrophages was detected by MTT method.Results MCSF could enhance SeGSHPx and SOD ac-tivities , moreover , it could prevent foam cell formationcaused by active oxygen and elevate the survival num-ber of murine macrophages.Conclusion The enhancement of antioxidase activitiesby MCSF may be one of the reasons that MCSF canprevents foam cell formation and retard the progressionof atherosclerosis.