The study of attached algal communities (phytoperiphyton) in 16 rivers included the analysis of their taxonomic composition, ecology and spatial distribution. The paper discusses the main principles of change in the structure and functioning of the attached algal communities. Special attention is given to the problems of development of the river continuum, the effect of drainage lakes and catchment urbanisation. The analysis of the taxonomic composition and structure of phytoperiphyton in river ecosystems revealed similarities in the composition of the communities, especially the dominant species, as well as similar average biomass values. Dominants are few, represented by species resistant to dynamic water load. It is indicated that widespread alkaliphilic or pH-indifferent oligohaline species prevail in ecogeographic spectra of algae. Quantitative parameters and spatial dynamics of the structural characteristics of attached algal communities is shown to depend on the hydrological regime of the river.