The article provides a comparative analysis of the existing spatial structure of urban settlement of the two largest agglomerations of our country – Moscow and St. Petersburg. Quantitative (dynamics of the number of settlements with the status of a city, dynamics of the population of cities, the number of houses under construction and the total area of residential units under construction) and qualitative (analysis of the automobile and railway networks) indicators are used. The following scientific methods are used in the work: statistical, geostructural, cartographic modeling, grouping method. 2002–2021 the two agglomerations are characterized by positive trends in population growth, which are associated with migration growth. The supporting framework of the Moscow agglomeration is represented by a uniform radial-circular type with a mixed monopolycentric model with a dominant core and the presence of large sub-centers, while the St. Petersburg agglomeration is a coastal type with a pronounced monocentric model and exclusive dominance of the core. On the basis of the existing supporting frames, to determine the stages of development of two agglomerations, a spatial typology of cities was carried out depending on the degree of their remoteness from the corresponding central points (nuclei). As a result, five orders (belts) with averaged transport availability isochrones were identified. Transformation processes of staged agglomeration development proceed most intensively within the entire Moscow agglomeration, which is at the stage of suburbanization. In the St. Petersburg agglomeration, the most active urbanized zone are cities located at distances of up to 50 km from the central point of the core, and it is characterized by a transition from the urbanization stage to the suburbanization stage