Abstract: Megasporogenesis and development of megagametophyte of the pistillate flower in Flueggea suffruticosa were observed by using the method of paraffin sections. The results showed that the pistillate flower of F.suffruticosa had epigynous ovary which was axile placenta; each ovary had 3 locules and bearing 2 anatropous bi-integument ovules in each locules. The ovules were crassinucellate and had nucellar beak and obturator. The development of embryo sac was of the Polygonum type. The mature embryo sac was consisted of two synergids and an egg cell near the micropyle, a central cell with two nucleus in the center, three antipodal cells by the side of chalaza. These results could provide basic data for the research of reproductive biology and pollination biology in Euphorbiaceae, meanwhile, for the research of plant taxonomy in Euphorbiaceae.

Key words: Flueggea suffruticosa, Euphorbiaceae, magasporogenesis, nucellar beak