It is important to study the effects of lipid oxidation on biological membrane, and how this affects physiological functions and causes disease We investigated the vesicular dynamics of a biomimetic membrane system consisting of an unsaturated phospholipid, 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC), and cholesterol (Chol) under oxidative stress We found that lipid vesicles with a DOPC Chol ratio of 50 50 are more susceptible to oxidative stress than homogeneous DOPC lipid vesicles