Abstract: Aim:To study the antiatherosclerosis mechanism of scallop skirt glycosaminoglycan(SS-GAG)by observing the effect of SS-GAG on the oxidation of low density lipoprotein in macrophage and on the activities of glutathion peroxidase(GSH-PX)and myeloperoxidase(MPO).Methods:The cell line was established by in vitro culturing mouse macrophage RAW264.7 was employed to study the effects of SS-GAG on the oxidation of LDL and the activities of relevant enzymes in macrophage via the assay of concentrations of malonaldehyde(MDA),conjugated diene,activity of GSH-PX,and MPO.Results:After macrophage incubation with LDL for 24 h,we found the enhanced activity of MPO,decreased activity of GSH-PX,and increased production of lipid peroxidation.Moreover,SS-GAG could increase the activity of GSH-PX but attenuate the activity of MPO.The decreased production of lipid peroxidation were also observed.There also existed dose-effect relationship in our findings.Conclusion:SS-GAG could depress the oxidation of LDL by degrading the activity of MPO and increasing the activity of GSH-PX.This may be one of its mechanisms of antiatherosclerosis action.