Despite previous scholarship on family history and demograghy by analyzing clan genealogies in East Asian countries, determining the criteria of likely inclusion in the genealogy remains critical. To establish the determinants of a genealogy register, this article addresses the substantial characteristics of the oldest extant genealogy in Korea, that is, that of the Andong Kwon clan, published in 1476. To determine the most important criterion for inclusion in the genealogy register, the author mainly compares the impacts of lineage lines, sibling birth order, and occupational title on this genealogy. The author finds that lineage lines and sibling birth order did not have a significant influence on the genealogy register, whereas the occupational title as an indicator of social status affected the genealogy register much more than did the other variables.