This paper discusses the historical development of the Rei ritual by examining the records dealing with rites. Next, utilizing the theories of religious studies and sociology, the existence of Rei, which was not included in the ancestral worship system nor in the traditional Confucian set of values, shall be analyzed structurally. As a result of this analysis it is shown that Rei rituals were regarded as vulgar folk religion. This view may have resulted in the lack of written records in official histories and manuals of rites. This paper also discusses the interaction between the state and the popular level of religious life. It is shown that Rei rituals were very popular among the common people and sometimes acted as models of governance in local societies. Furthermore Rei rituals included ideas about the salvation of the dead that shares commonalities with other organized religious beliefs. Because this it can be seen that both upper and lower levels of society held similar ideas regarding death.