Abstract: This paper deals with a histological observation of somatic embryogenesis of soybean cultured in vitro, an extension to our previous on “Plant regeneration from immature embryo -culture of soybean via somatic embryogenesis”. The results are presented as follows: The embryonic cell mass appeared at first by initiating from the cells of epidermis and 1–3 layers of subepidermis of the immature cotyledon which underwent de-differentiation. After that, the embryoic cell mass continued to divide and developed further into embryoids. Later on, the embryoids developed into plantlets throughout globular, heart-shaped, torpedo-shaped and cotyledon stages. Apart from this, during process of embryoid induction, another noticeable feature was that the embryonic cell might also be produced in the deeper layers beneath the epidermis of cotyledon. They looked, irregular and developed into globular or heart-shaped cell mass. Judging from their origin, they might be “esdo-embryoids”. Whether these “endoembryoids” could be further developed is a question that warrants further studies.

Key words: Soybean, Histological studies, Somatic embryogenesis