Essential proteins are taken from cellular membrane to intracellular components through receptor-mediated endocytosis (Hopkins and Trowbridge, 1983) or Clathrin-mediated endocytosis (CME) (Maib, Smythe and Ayscough, 2017),which it comes from association of transferrin and pits in transferrin trafficking pathway. Endocytic pathway has been discovered by Goldstein and his friends when (LDL) low density lipoprotein has been taken from cellular membrane and fused with lysosome (Maib, Smythe and Ayscough, 2017). One of these proteins is transferrin ,which is known the major carrier of iron in the blood that transport the iron from liver and intestine to cells to do their cellular activities (Harvey et al., 2000). Transferrin receptors are presented in all cells and these receptors bind to ferro-transferrin outside cells to activate endocytosis and apo-transferrin secretion (Harvey et al., 2000). In transferrin cycle inside cells, transferrin receptor-ligand bind to apo-transferrin for transport ,and finally iron is given from transferrin complexes to endosome structure ,and cellular receptor will be attached again with apo-transferrin (Harvey et al., 2000). The previous method shows internalizing of transferrin with its ligand and receptors in cells and delivering them to lysosome (Harvey et al., 2000). Normally, the highest concentration of transferrin present in the liver and intestine because the majority of iron is there but, in some situations, transferrin can also be higher in cancer cells (Ng et al., 2002) because nutrients are needed in their uncontrolled growth. On the other hand, recycling “exocytosis” involve returning of free-iron transferrin (apo-transferrin) and receptors from early endosome to cell surface (Geissbuehler et al., 2012). This process is done by GTPases and actin regulators (Mayle et al ,2012). In this report, I will evaluate the internalisation and recycling of biotinylated transferrin in A431 cells incubated in different period of time to show how this protein is utilized. Additionally, because transferrin present on all cellular services, avidin is added to bind to biotinylated transferrin (Ng et al., 2002) to prevent outer transferrin from an estimation after internalisation.