Chosŏn Korea was severely affected by both Japanese and Manchu invasions in the early 17th century. However, an accurate assessment of the impact on the population remains unknown. This is because the Chosŏn government failed to assess the demographic impact of the wars. This study focuses on two primary sources - genealogies and household registers. It examines the victims of the war and explores their potential as sources for historical demographic research. It is clear that both materials have remarkable characteristics for studying the unique demographic phenomena of the Chosŏn family and the dynamic population trends in pre-modern Korea, despite their significant limitations as historical demographic sources. The potential of both sources for historical demographic research is demonstrated by the proportion of female-headed households among the upper class and the proportion of concubines among the partners of male household heads.