The notion of the common family is an important part of The Republic(by Plato). The notion includes the ways to build the family and its theoretical basis. The clearest characteristic of the common family is “common”, referring to both relations of human beings and their property. In order to build the common family, it is necessary to maintain marriage that should be rational and sacred. Comparing The Republic with the family values in the Pantisocracy of China, the biggest difference is how to understand humanity. The former focuses on the reason in the transcendental world, and the latter is based on emphasizing the virtue of kindness in the experiential world. The notion of the common family in The Republic has a profound impact on the history of the eastern and western civilization.