Abstract: Biodiesel, with the most hopeasa reproducible substitute for fossil energy, is getting more and more global attention because of its good environment-protective effects. Plant oil, the main resources of biodiesel, is stored and accumulated in seed oil bodies, which are the plant oil storage organelles, as the most economic and effective food reserves for seed dispersal, seed germination and seedling growth. This paper discusses the advancements in ultrastructure, composition and functions, and biosynthesis and degradation of seed oil bodies.