Surfactants have been widely used in cosmetics, detergents and pharmaceutical industries. These applications are always accompanied by surfactant-induced skin irritation which is linked to surfactant interaction with the components of the outermost layer of skin: dead corneocytes and extracellular lamellar lipid. Therefore, for surfactant-induced skin irritation, the interaction of skin lipid with surfactants should be studied. In this proposal, phospholipid vesicles are been used as a first step to model the lipid in skin. SANS will be employed to study the interaction of phospholipid vesicle with cationic/anionic surfactant mixtures. We try to reveal how the surfactant mixture incorporate into and disintegrate the phospholipid vesicle and explain the observed efficacy of mixed surfactants.