Abstract: The Broomcorn millet (Panicum miliaceum L. ) is a crop of Graminese Panicene. There was an anatropous ovule in the ovary which was double integument and crassinucellate ovule tissue. Its embryo sac was polygonum type which had 8 nuclei and 7 cells.In the ripe embryo sac, there were 4 - 5 antipodal cells, and one ofthe synergids degenerated before fertilization, but the polar nucleus did notfuse.,In the process of double fertilization, the egg had 3 nuclei after fertilization. The endosperm nucleus divided earlier than that of zygote after two pole nuclei and sperm nucleus had fertilized successively.The free-nucleus stage lasted appoximatcly 1.5-4 days, and at the 5th day, the endosperms began to accumulate starch. The time of zygote dormancy was about 20 hours. The first division was cross. The accomplishment of embryo differentiation needed about 12 days.And at about 22-23 days, the seed got mature. The antipodal cell removed after G days of flowing when the embryo began to differentiate and starch in endosperm began to accumulate largely.

Key words: Broomcorn millet, Embryo, Sac antipodal cell, Endosperm nucleus, Polar nucleus