Field stidies in the Protva drainage basin elucidated the drainage network evolution. Some small valleys and erosional landforms date back to Pre-Quaternary time. Erosion and alluviation stages alternated throughout the Pleistocene, erosion took place early during interglacial or warm phases, alluviation proceeded mostly during early glacial, full glacial and late glacial time. Erosion - alluviation alternation was mostly controlled by climate and in lesser degree by isostasy and neotectonics. Most of the valleys were inherited from Pri-Quaternary forms and developed continuously. A few cases of changes in drainage pattern are known to occur during cold phases. The data obtained suggest that small and large rivers of the Russian Plain have much in common, though small rivers are somewhat quicker in their response.