This article aims to the exploration of customs regarding to the family and succession relations and the development of the law. First is to define the “kinship status,” “relations,” and “customs regarding to the kinship (family and succession) relations” etc. Second is to refer to India, South Korea, South Africa, the Hebrews, and Taiwan experiences for understanding different aspects of applying the customs regarding to family and succession relations in the changing societies. Furthermore, this research examines laws related to this issue in Taiwan after October 25th, 1945, as well as a variety of customs (mainly from 1895 to 1945). And a survey of related cases are analysed, such as “A minor raised to be the future daughter-in-law,” “A minor raised to be the future daughter-in-law, whose future husband or husband die in early age or soon after their marriage,” “Adoptee as son-in-law,” and “Heir adopted after the death of the decedent” etc. To keep the order of good, fair, and stable kinship relations, this research proposes new measures for legal amendment and legislative policy; and seeks a balance between the related interests in the evolving laws and changing societies.