The author had questions about slaves emerged countless in Census register(戶籍) Punjaegi(分財記) such as from simple questions of their food, clothing and the relationship between slaves and owners to historical features of slaves. So, author wrote doctoral thesis on this theme. The author examines focusing two points, Ibyŏk(立役) and Napkong(納貢). Chapter 1 examines the origin and institutionalization of Napkong(納貢) as prerequisite identifying of slaves. In chapter 2, investigates details and features of Chakkae(作介) and Sagyŏngje(私耕制). Chapter 3 reconstructs actual living through Mukchaeilgi(默齋日記), diary of aristocratic elite in 16th century. Chapter 4 describes slave registration, Ch’uswae(推刷) and property inheritance.