Abstract:We observed tissue sections of single hybrid of maize 328 and its parents during early embryogeny, determining ATP ase activities and observing plant features. The results obtained show that maize embryogeny can be divided into three periods, that is, 1) The period of 3–7 days after pollination is known as an original embryonic period. 2) The period of 9–20 days after pollination is known as the period of undergoing rapid differentiation of all the tissue organs. 3) The period of 25–45 days is known as the period of further differentiation, perfection and elongation of organal system. The size of volume of hybrid embryo is between its parents during the second period. That of the hybrid embryo during other two periods is larger than that of its parents. Hybrid embryo always shows that the number of its cells is more, its cells are closer together, the colour of the stained cells is darker, the cells differentiate clearly, the time that embryonic organs differentiates lasts longer. The results of determinig ATP ase activities it may be seen that during 1–2 days after pollination ATP ase activities in hybrid ovaries are obviously higher than in its parents’ ovaries. On the third day after pollination ATP ase activities in hybrid ovaries once go down. After that ATP ase activities go up again. During 15–45 days ATP ase activities in hybrid embryo (unincloding endosperm) are all higher than those in its parents. Hybrid 328 has advantage over its parents in yielding capacity, plant height, spike length, number of seeds per spike, 1000 seed weight. The results show close correlation and supplement among cell differentiation ability, ATP ase activities and plant features.