Atherosclerosis is associated with the presence of extracellular lipid droplets and large fatty deposits, both of which are to be covered at the surface mainly by zwitterionic phospholipids. The development of atherosclerosis is often associated with the accumulation of calcium. Furthermore, the presence of glycosaminoglycans directly underlying fatty deposits in human aorta has been demonstrated. Also, the possible involvement of the interaction between sulfated polysaccharide and lipoprotein in the development of atherosclerosis has been suggested in view of the presence of both low density lipoproteins and glycosaminoglycans, as well as their complexes, in atherosclerotic aortas. Therefore interactions of sulfated polysaccharides with low density lipoproteins which serve as a vehicle for cholesterol and cholesterol ester and with zwitterionic phospholipids have been studied extensively by a number of workers to provide mechanisms. In this paper, the mechanism of the interaction of sulfated polysaccharides with low density lipoproteins and the mechanism of the interaction between sulfated polysaccharides and zwitterionic phospholipids are reviewed. The possibility of the occurence of these interactions in the body are also considered.