The experiment was conducted to study on the physiology of developing embryo and endosperm degradation during germination of Zea mays seeds treated with GA 20 and B-Nine 5000 ppm. Data obtained can be summerized as follows : 1. Swelling of seminal root increased the section of GA treatment more or less, on the other hand, the section of B-9 treatment inhibited slightly. 2. According to elapsing of seeding date, epithelial cell of Scutellum expansed in size, and the space of cell increased, that degree was enlarged as follows ; the section of GA, the section of Control, and the section of B-9. 3. According to the elapsing of seeding date, the formation of vascular organization embryo became clearer little by little, the lignification of vascular B-9 treatment section rather higher than the other section. 4. The degradation of Starch Grain is composed of near part of epithelial cell of Scutellum, the shape of degradation radiate from element of a disk shape, and the speed of degradation is the section of GA, the section of Control, the section of B-9 in turn.