The subject of the study is the transformation of marriage and family relations of Transcaspian Turkmens under the influence of the confessional policy of the Russian Empire, which included the territory of Transcaspia in its borders in the last third of the XIX century. The use of concrete historical, comparative legal, structural and systemic methods in the study allowed us to draw conclusions relevant for filling historical and legal gaps in Russian-Turkmen relations. Despite the tolerant attitude of the imperial authorities and even the support of some Muslim-legal (religious-ceremonial, family-household and moral) prescriptions, Sharia could not subdue all aspects of Turkmen life and replace customary law (adat), which played a major role in all periods of development of Turkmen society. Sharia were clarified and applied. During the imperial period, thanks to the activities of the Russian administration and the central government, the jurisdiction of Muslim law expanded significantly; it received a judicial tribune in the form of such a centralized body as the Extraordinary Congress of People's Judges, with the help of which some guiding principles of both Adat and Sharia were clarified and applied. The rapidly changing socio-economic situation caused by the close interaction of traditional Turkmen institutions with Russian state bodies (changes in the economic and lifestyle of the local population, binding to market relations, non-belittling of the role of Islam and Adat in its spiritual life, their compromise combination with the general laws of the empire, the practice of improved forms of popular justice) led to a change in the traditional legal consciousness of the Turkmen. The desire of the imperial center and the Russian administration of Transcaspia for the regulatory and legal regulation of life in the family, marriage and other spheres allowed this people to gradually integrate into the all-imperial state and legal space, while preserving stability, family and religious values.