Abstract: The ovule is the source of the embryo sac and the progenitor of the seed, which plays an important role on plant reproduction. A few mutants had been identified in recent years, such as sin l, bell, ovm2, ovm3,whose phenotypes show that both integuments and embryo sac develop abnormally,and these mutants are female-sterile. At the same time, some ovule-specific cDNA clones in Orchid and Petunia flowers had been isolated and among them MADS Box genes may be responsible for the ovule differentiation and formation.