The thesis focuses on family aspects, kinship and kinship terms of seven Tai ethnic groups in the northeastern region, including Isan Thai, Korat Thai, Yo, Yoy, Saek, Phu Thai, and Kalerng. There are 665 kinship terms used by the seven ethnic groups. They are divided into terms used by the same family, same group, across the group, and specific group. These terms have been orally transmitted from generation to generation. They are imitated closest to their mother tongues even though they are linguistically influenced by mainstream media, education and experience. However, mother tongues are most influential at the local level and are used as a medium of communication on a daily basis (pp. 2, 7. 37, 69).