Jozef Obrebski investigated the family in Polesie as ethnologist and sociologist and he described the problem in both diachronic and synchronic approaches. He emphasized the ethnic aspect in connection with the processes of modernization of the traditional society and cultural system in this territory. Obrebski was particularly interested in the transformations in the Polesie traditional family. He analyzed the problem in his works 'Polesie archaiczne' and 'Panska szkola i muzyckie dzieci', both written on the basis of his ethnosociological expeditions to Polesie in 1934-37. J. Obrebski analyzed the big traditional family and its patriarchal structure as the basis of economic and social life in the traditional peasant society and main resource of its traditional culture. His works are very valuable for modern investigations of the Polesie family, due to rich factual material which the author obtained from his respondents, and cited in detail. His description of the system of big traditional family became the excellent example of the functional analysis in the investigation of such problems, especially some processes of the disintegration of the traditional family.