Based on original data (450 samples from 115 streams of European Russia middle latitudes--from Pskov to Kostroma Regions) the attempt is made to describe the overall diversity of rheophilic communities dwelling on streams bottom and in macrophytes. In total, 39 community types were identified by the Brown-Blankuet method; their taxonomical and structural characteristics are described; the associations with biotopes are outlined; and a biotopical nomenclature is proposed. All communities are subdivided into four biotopical classes: crenal (springs and springbrooks with mixed substrates), rhitral (stony and woody substrates), phythal (macrophytes), and pelal (soft ground). It is shown that all communities may be divided by their organization as R-type of M-type community. 36 out of 39 studied communities belong to R-type and are characterized mainly by prevalence of insect, unstable dominance, and rather distinct association to the biotope. In M-type communities (3 out of 39 studied communities) eurybiontic mullusk Viviparus viviparus and amphipod Dikerogammarus haemobaphes predominate; these communities are interbiotopic, with stable species structure and high total abundance. The effect of the study spatial scale on the definition of communities is discussed along with problems of the communities dynamics.