In the traditional Chinese postpartum ritual,newborn baby was not accepted as family member from the beginning. It was through the four ritual periods of the"isolation","purification","reorganization"and "incorporation",which separated newborn baby from the supernatural world,passed it through the transition of"Mother of Nature",and finally incorporated it to this world’s human society. "The Rites of Passage"after childbirth made human biological reproduction process have more social and cultural meaning,and realized the real reproduction of human beings and their whole social relationships. This research is also inspiring to nowadays postpartum care work and family relationship in the background of instrumental rationalization.