The authors described shortly the metabolism of lipoproteins, specially the recently acquired data on their physiology. First are reviewed the chemical and physical characteristics of lipoproteins, of apoproteins and their functions, then the enzymes of vascular metabolism of lipoproteins, specially apo B and apo B, E receptors. The various lipoproteins chylomicrons, VLDL, LDL and HDL are described from synthesis to catabolism and by the way, the various pieces of this metabolic puzzle are placed.