The methanol extract of Taraxacum coreanum Nakai (Compositae) was examined on the in vitro oxidation of human low density lipoprotein (LDL). It is well known that LDL oxidation induced artherosclerosis, if we can protect LDL oxidation process, excess plasma lipoprotein accumulation into the arterial lesion prone areas can be blocked. The methanol extract was treated with oxidized LDL which was incubated with $16;{mu}M$ $Cu^{2+}$ for metal catalyzed oxidation and TBA value, mobility on agarose gel and formation of conjugated diene and change of vitamin E were determined for the evaluation. The extract showed antioxidative effect at concentration $200;{mu}g/ml$ on LDL oxidation.