Abstract: This paper deals with embryology morphology of Zizania L. and its relatives. A total of 4 genera 7 species and 2 subspecies were examinedunder light microscope. The results are as follows. 1. The genus Zizania L. belongs to tribe Oryzeae as show by its embryo formula F + PP. But it is different from others by its cylindric caryopsis, scutellum narrow and very long etc. Hance it may be considered as anisolated subtribe Zizaniinae in Oryzeae. 2. The evolutionary trend of the taxa seems that, gen. Oryza L.is more primitive than others, such as Zizania related to Oryza by thecommon character of their caryopsis, Zizaniopsis related to Oryza by theircommon characters of scutellum nearly triangular and epiblast connectedwith scutellum, gen. Chikusichloa related to Oryza by their common chara-cters of scutellum elliptic obtuse at apex. Hance it may be considered asthat they may be derived from the ancient stock which has also given riseto the genus Oryza, and therefore paralled evolutionmay have taken placein Oryzeae. 3. The characters of embryo morphology under LM support the division of the genus Zizania into 4 species, 2 subspecies in the world, i.e. Z. latifolia (Griseb.) Turcz, ex Stapf, Z. texana Hitche., Z. aquatica L. subsp. aquatica, Z. aquatica subsp. brevis (Fassett) S. L. Chen, Z.palustris L. subsp. palustris and Z. palustris L. subsp. interior (Fassett)S. L. Chen. In this group, Z. latifolia is the most primitive species.

Key words: Zizanta L., Embryo morphology, Systematic evolution