This article describes the morphological aspects of the flower and seed development of Robinia pseudoacacia Linn. in Nanjing district, including the process of megaEporo-genesis and microsporogenesis, the development of female and male gametophytes, fertilization, development of embryo and endosperm and seed formation, which can be summarized as follows:1. The megaspore mother cell and the microspore cell both come out during the first decade of April, with the former developing later than the latter.2. The crassinucellar ovule is campylotropous and the embryo sac is of the Polygonun type.3. The endosperm is of the nuclear type and its nuclei are smaller than those of the free nuclei.4. The embryogenesis is of the Solanad type and the mitosis of the zygote takes place earlier than that of the primary endosperm nucleus.