. Water plants and coastal riparian plants are an integral part of the habitat forming component of water ecosystems in Saratov region. This article gives a review of long-term research of fl ora in many water reservoirs and water streams of the Saratov region. The analysis of literature in its historical aspect showed that the degree of scientifi c knowledge about water fl ora in the Saratov region is still insuffi cient despite multiple research projects conducted at the end of the 20th and beginning of the 21st centuries. At the moment some research is being conducted concerning the inventory and monitoring of fl ora and plants in the water reservoirs and water streams of the Saratov region. In this work a complete list of water plants and coastal riparian plants is represented. The fl ora of water vascular plants contains 103 types (including hybrids) of 54 species, 32 plant families and 3 plant divisions. The leading plant families are Potamogetonaceae, Cyperaceae, Typhaceae and Poaceae. The most widespread species are Potamogeton represented by 18 types and 3 hybrids (13 % of all fl ora). Multi-species are Typha, Carex,Scirpus and Lemna. To identify the proportion of water species in fl ora of water streams and water reservoirs, the hydrofi tness index IHg was used. It showed that the most diverse water fl ora exist in the Volgograd water reservoir and lakes. In ponds and oxbow lakes coastal plants play an essential role which can be explained by fl uctuations in the levels of these water bodies. In water reservoirs and streams of the Saratov region the most highly active ones are Phragmites australis Potamogeton pectinatus, Typha angustifolia, Nuphar lutea, Sparganium erectum. The percentage of active types makes up only 5 % of all water fl ora. Among registered vascular plants 30 types are included in the Red Book of endangered species of the Saratov region. In the researched fl ora 9 invasive species were detected, such as Bidens frondosa, Elodea canadensis, Zizania latifolia, Typha laxmannii, Acorus calamus, Hydrilla verticillata, Vallisneria spiralis, Lemna gibba, Lemna minuta.