Choson`s social customs concerning marriage and childbirth are known to have included early marriage, a preference for sons, and a ban on female remarriage. This study estimated the patterns of marriage and age at marriage in Choson society, and the factors that affected changes in net reproduction. While women`s age at marriage was generally stable during the 15th-19th centuries, this began to change from the 20th century onwards. Meanwhile, men`s age at marriage exhibited a tendency to continuously decrease. Moreover, men`s age at marriage was also found to be affected by the adult mortality rate and continuously increased after the 18th century. Choson`s yangban adopted the strategy of early marriage to remedy this situation and ensure the continuation of their lineages.