Like all nationalities, selection of dates and people is also a usual etiquette and custom of Chinese; therefore, it is a topic which deserves thorough studies. Yi-Li(《儀禮》) is the earliest ancestor of the books of rites in later generations. It meticulously records each practice of rites in ceremonies, such as puberty, weddings, funerals, worship, archery, and pilgrimage. However, in Yi-Li(《儀禮》), some chapters record distinctly the practice of rites and norms according to divination and the selection of dates and people, but some do not. Some are detailed but some are not. Do the ones which are distinctly recorded succeed to anything? Or are they mapped out by the author? Do the unrecorded rites mean that they have no need of divination? What are the reasons? Can we infer that whether or not there are omissions in Yi-Li(《儀禮》)? If we can, do they base on other chapters in Yi-Li(《儀禮》)? Or do they base on other documents? What is the relationship between these situations and the age when Yi-Li(《儀禮》) was completed and the era which is reflected by each practice of rites? We will discuss these questions individually in this paper.