The contents of this work were concerned with kinship and family structures as well as kinship and kinship roles of the Phu Tai ethnic group at Ban That Village, Warichaphum District, Sakon Nakhon Province. The population consisted of 50 household heads from 12 families, community leaders, and folk scholars. The villagers were the Kapong Phu Tai, who migrated from Laos at different periods. It was found from the investigation that the family structure was of an extended type and there was a seven generational relationship in the family. The kinship structures were of two types: by blood and by marriage, and kinships could be expanded through Phor Lam, making the whole villagers related and helping one another in terms of village administration, education, livelihood, and ritual arrangement.