Abstract: On the basis of the detailed studiy on the embryology in Nitraria sibirica Pall., the authors compared the characters of this genus with Those of the other genera in Zygophyllaceae, i.c.Fagonia, Scetzenia. Zygophyllum, Peganum, Balanites, and ered a distinct difference on the author wall development. microspere tetrads, gynoecium, ovule number in each locule, nucellus development, the presence or absence of the intemont tapetum formation of micropyle, endothelium, number of archespore and megaspore mother cell, suspensor developmnet, polyembryony, fruit dcvclopmnet, etc. The conclusion supports that the Nirtfaria should be separated from Zygophyllaccac, and set up a family Nitrariaceac.

Key words: Nitraria, Embryology, Systematic position