The author provides in depth knowledge of understanding all aspects of physiology of soybean. It is written lucidly, systematically, and in depth. It provides recent information and findings, explained with illustrations to express the ideas and concepts vividly to university students and researchers to further enrich the subject for improvement of the crop for enhancement of productivity to cope with the future demand. It describes the physiology of growth, development, flowering, Pod set and seed yield as well as C, O, N and Oil metabolisms - their hormonal regulations under normal and stress environmental conditions. Molecular approaches are also described.