Under the background of "the Belt and Road" and "the economic corridor of China, Mongolia and Russia" initiatives, this paper studied the urbanization development level, eco-environment development level, the coupling coordinated development degree between urbanization and eco-environment, and their spatial differentiation of the eastern Russia. Combining with the Population-Economic-Sociology model and Pressure-State-Response model, the paper first built two index systems of urbanization and eco-environment. Then based on the comprehensive weighting method of entropy weight and variation coefficient weight, we calculated the urbanization development level with regard to the population urbanization, economic urbanization and social urbanization, and the eco-environment development level with regard to the eco-environment pressure, eco-environment state, eco-environment response during 2005-2018. Next, the coupling coordinated development degree of the urbanization and eco-environment development level was measured by the coupling coordination degree model during 2005-2018. Finally, the spatial differentiation of the urbanization development levels, the eco-environment development levels, and their coupling coordinated development degree were performed respectively by using ArcGIS. The results were as follows. (1) The economic urbanization and eco-environment pressure were the main factors that affected the urbanization development and eco-environment development, respectively. The comprehensive urbanization development level, the coupling coordination degree between urbanization and eco-environment of eastern Russia had increased from 2005 to 2018. The comprehensive eco-environment development level had decreased from 2005 to 2018. However, they were still in the uncoordinated stage, and their internal development showed the changes from the urbanization lagging to the balanced development. (2) From 2005 to 2018, the urbanization development level, the coupling coordination degree between urbanization and eco-environment of the Siberian Federal District were higher than that of the Far East Federal District. The eco-environment development level in Siberian Federal District was roughly balanced to that in the Far East Federal District. Most of the federal subjects were in the uncoordinated stage. (3) The urbanization development level, the eco-environment development level, and their coupling coordinated development degree were all spatially imbalanced in the eastern Russia. They showed the "High in West, Low in East" spatial pattern, which in generally displayed the tendency of space attenuation from the west to east. The areas with high levels were concentrated in the Novosibirsk Region, Altay Territory, Kemerovo Region, Krasnoyarsk Territory, and Irkutsk Region. The areas with low ones were mostly in the Republic of Altay and Chukotka Autonomous Area. Finally, we suggested policies and strategies that could boost the coordinated development of urbanization and ecological environment in eastern Russia.