Sustainable rural development is identified mainly by means of ecological solutions. At the moment, more and more attention is given to natural and sightseeing values of our envi-ronment, and hence, to biodiversity. The aim of the research conducted in the years 2005−2008 was to assess the floristic diversity of grass communities in the middle part of the Wieprz river valley (Lublin region) depending on the habitat and ways of use. The moisture of habitat and the use of sward influence the formation of grass communities Molinio-Arrhenatheretea and Phrag-mitetea classes, which were characterized by average floristic diversity and the presence of endan-gered and protected species. Grass communities in river valleys require preservation and protec-tion not only for economic reasons but also because of the floristic diversity and ecological envi-ronmental functions, and thus for the sustainable development of rural areas.