Dryopteris goeringiana was chosen as material. The artificial cultivation of gametophyte generation was taken in simulation natural conditions. With paraffin method, the whole process of embryo development was recorded. The results showed that: (1) the embryo development was perpendicular to the gametophyte plane and the dorsal abdominal axis, which conformed to the prone type. The first division of the zygote was parallel to the long axis of the archegonium. The primitive cell of organ formed in the 16cell embryo period, and the formation of the first leaf primordium was earlier than the first root primordium. In the hippocampal embryo period, the first leaf primordium and the first root primordium broke through capshaped parts, and then formed obvious vascular bundles of the first leaf and the first root, respectively. Free nuclei existed during embryonic development. (2) This paper presented 14 point line graphs that the process from zygote formation to the first leaf and the first root maturity, including the division mode of early embryonic cells, the characteristic of the cell nuclei and nucleoli, organogenesis order and their mutual relations. It was summarized that the embryonic development mode of leptosporangiatae in details, and supported Nayars Phyllorhize Theory. This paper advocated the stems from leptosporangiatae and seed plants were different in essence, and the two groups were parallel development.