Developmental biology is one of the important fields in basic biology that has a profound impact on human health. It initiates from the morphological observation of chick embryo development to the unraveling of the molecular control of embryonic development in a variety of organisms. It is a miracle to learn how a single cell develops into a fully functional adult and we still do not know much about the underlying mechanisms for different processes during development. We will discuss the basic principles and molecular controls of embryonic development. We will emphasize the progression from gametogenesis, fertilization, cleavage to gastrulation (i.e., the formation of the gut). We will also cover cell fate and embryonic axis determination. The popular experimental models used by current developmental biologists will also be examined in detail. We will go over the formation and derivatives from three germ layers, ectoderm, mesoderm and endoderm. Lastly, tissue and organ regeneration and the progression of regenerative medicine will be highlighted.