Transfer cells have important roles for transportation across the cell membrane in plants. They have distinct ingrowth of cell walls and high activity of proton-ATPase in their invaginated cell membrane. Protoplasts prepared from transfer cells show resistance to osmotic shock and a detergent showing that their cell membrane has different constituents from normal cells. To reveal the process of differentiation, transfer cells were induced by iron deficiency in root tips of sunflower (Helianthus annuus) in hydroponics. In this present work, we tried to reveal cytological factors affecting on transfer cell differentiation using various inhibitors.