The article reports on the results of a study on the ichthyological diversity observed in the middle part of the Amur basin on the territory of the Jewish Autonomous Region (JAO) and the adjacent border territory of the People's Republic of China. The research covers the issues of diversity, distribution and ecological specificity of fish for the families Cobitidae and Balatoridae in the water bodies and watercourses of the region. The research summarizes and amends information on the distribution of the Cobitidae and Balatoridae families in the Bastak Nature Reserve (Russian Federation), and in the Honghe and the Bachadao reserves (China), as well as in a number of rivers of the JAO (Amur, Dobraya, Bijan, Bira, Ikura, Tunguska, In, Zabelovka, Gari, etc.), and rivers of the adjacent Chinese territory (Amur, Yalu, Sungari). The paper confirms the families’ habitat within the location under study, and provides information on the distribution of eight members of the family Cobitidae: Cobitis lutheri (Rendahl, 1935), Cobitis melanoleuca (Nichols, 1925), Cobitis choii (Kim et Son, 1984), Misgurnus anguillicaudatus (Cantor, 1842), Misgurnus nikolskiy (Vasilieva, 2001), Misgurnus mohoity (Cantor, 1842), Paramisgurnus dabrianus (Dabry de Thiersant, 1872), Parabotia mantschurica (Berg, 1907), and three members of the family Balatoridae: Barbatula toni (Dybowski, 1869), Lefua costata (Kessler, 1876), Lefua pleskei (Herzenstein, 1887). The article contains data for the observation period from 2001 to 2019. The information is new for the area under investigation.