The article discusses the issue of passing ethnic identity from generation to generation among the Russian-Ukrainian population of Russia and the process of forming a dual identity. Based on studies conducted in 2020-2021, the authors reveal the process of transferring ethnic identity through the lens of a multinational family, intergenerational ties. Having analyzed five generations of respondents, we can conclude about the conscious choice of the majority in favor of the Ukrainian component of identity to a greater extent in connection with the origin of the ancestors, and the Russian component due to living in Russia. With each generation, there is an external “extinction” of Ukrainian identity (for example, a decrease in the use of the native language) and the formation of a dual nationality among young people - Russian-Ukrainian, but with the predominance of the Russian component, which is associated more with socio-political assimilation.