Abstract: The differentiation of aleurone cells of Coix lacryma-jobi' began at 10 days after pollina tion (DAP). At this time many lipid bodies were formed in the cellls. By 15 DAP. the granular or flocculent proteins were accumulated in the vacuoles of the aleurone cells. By 20 DAP, the small vacuoles filled with protein deposits became the aleurone grains. The mature aleurone cells were characterized by a large number of lipid bodies and aleurone grains. In the cytoplasm the'organelies Were'not present. but ribosomes, Some aleurone grains had one or several spherical bodies in the protein matrix and some had one electro-dense body. Starch grains and lipid bodies produced in the sub-aleurone cells at 10-15 DAP. A great number of protein bodies fromed but lipid bodies disappeared at 15-20 DAP. The protein bodies arose from the vesicles or intracisternal dilations of the rough endoplasmic reticulum and had a central core and concentric rings. Some of them also possessed radiative fissures.

Key words: Coix lacryma-jobi: Aleurone cell, Aleurone grain, Sub-aleurone cell and protein body, Development, Ultrastructure