Lipid-transfer proteins(LTPs) are a group of basic, small (9 ku) proteins which transfer lipids between biomembranes by in vitro assays. So they are thought to participate in the lipid transferring during biomembrane synthesis. Their purification, structure, gene expression and biological functions have been studied in various monocotyledonous and dicotyledonous plants. The latest studies found that they are secreted and located in the cell wall, and that it is suggested that plant LTPs are possibly related with cutin formation, defense reactions against phytopathogens and plant adaptation to various environmental stresses.