Abstract: On the basis of the previous studies with light microscopy, we attempted to use TEM observing the early development of the endosperm in Nitraria sibirica Pall.The endosperm undergoes three developmental phase: free nuclear endosperm, cellularization, and disintegrative and absorbtive phase. At the free nuclear stage, the nuclei are surrounded by mass of dense cytoplasmic matrix.

Key words: Nitraria sibirica