Since CORINE Programme, the term habitat has become common in Europe, in the strict sense, it means living place, i.e., the abiotic environment where an organism lives or a distinct biocenosis. The habitats from the Republic of Moldova are poorly studied, we aren’t fully aware of the entire network of habitats in our country and we don’t have their characteristics. The phytosociological investigations of grassy vegetation in rocky areas from the Dniester-Prut interfluve revealed two important habitats of high conservation value for Europe's nature, they are part of Inland cliffs and exposed rocks subclass (62), Inland rocks, screes and sands class (6), according to the PALAEARCTIC HABITATS classification system where the habitats of Romania are described. Floristic nomenclature. The average annual temperature and annual precipitation.  1. Habitat RM(R) 6223. Ponto-Sarmatic communities, in fissures of limestone cliffs, of the association  Sempervivo ruthenici-Schiverckion podolicae, Pînzaru  et A. Ruschuk 2009. This habitat, R6233, described on the basis of the association Asplenio-Schivereckietm Mititelu et al. 1971, is corrected and completed in this paper.  Plant associations: Sempervivo ruthenici-Schivereckietum (Mititelu et al. 1971) Pînzaru et A. Ruschuk 2009, Sedo acri-Saxifragetum tridactylitis Pînzaru 2015, Sedo acri-Allietum luisitanici Pînzaru(2006) 2015, Asplenio ruta-murariae-Allietum flavescentis Pînzaru ass. nov, prov. Distribution: Romania (Prut Valley), Republic of Moldova (Dniester and Prut river basins), Ukraine (Dniester river basin), Russia (Southern European part). Area: some hectares. Sites: Altitude 50-250 m. Climate: T = 8-10°C, R = 500-700 mm. Relief: petrified limestone cliffs, diverse exposure, inclination of (2-5) 15-60°. Rocks: shell-limestone, coral-reef limestone. Soils: orthents. Structure. It is a pioneer, xerophile, calciphile habitat, includes reef rocks from the hilly zone. Mono- or double-layered phytocoenoses with a coverage rate of 30-50 (-70) %.  Floristic composition: Dominant species: *Schiverckia podolica, *Sempervivum ruthenicum, *Saxifraga tridactylitis, *Allium luisitanicum, Allium flavescens. Other important species: *Aurinia saxatilis, *Asplenium ruta-muraria, Arabidopsis arenosa, Sedum acre, Allium paniculatum, Gypsophyla collina. Phytocoenoses include also a large number of species of the Festucion valesiacae association, but with few specimens. Conservation value: high, includes species protected by the state, marked with an asterisk. 2. Habitat RM6224. Western Ponto-Sarmatic communities, on friable, dusty Sarmatian limestone, of the association Genisto tetragonae-Seselion peucedanifolii Pânzaru 1997. Plant associations: Genisto tetragonae-Seselietum peucedanifolii Pânzaru 1997, Thymo moldavici-Helianthemetum cani Pânzaru 1997, Sileno supinae-Pimpinellietum tragii Pânzaru 1997, Astragalo pseudoglauci-Peucedanietum ruthenici Pânzaru et A. Ruschuk in A. Ruschuk et al. 2005, Thymo sibthropii-Seselietum hippomarathri Pînzaru et Coldea 2006. Distribution. Middle and upper basin of the Dniester River (Republic of Moldova, Ukraine). Area: some hundreds of hectares. Sites: Altitude 50-250 m. Climate: T = 8-10°C, R = 500-700 mm. Relief: steep slopes, diverse exposure, inclination, usually, of 15-50°. Rocks: crumbly limestone of Middle and Lower Sarmatian. Soils: absent or a thin layer of rendzina which contains a significant amount of limestone gravel.  Structure. It is a pioneer, xerophile, calciphile habitat, includes some exposed Sarmatian limestone from the hilly zone. Double-layered grass cover, coverage rate of 40-70(80-90) %.  Floristic composition. Dominant species: *Genista tetragona, *Seseli peucedanifoliu, Thymus moldavicus, *Koeleria moldavica, *Silene spergulifolia, *Linum tauricum, *Pimpinella tragium, *Astragalus vesicarius s.l., *Helianthemum canum, *Peucedanum ruthenicum, *Scutellaria supina, *Alyssum gmelinii, * Paronychia cephalotes, Thymus sibthriopii, Seseli hippomorathrum. Other important species: *Ephedra distachya, *Convolvulus lineatus,* Helianthemum nummularia, Haplophyllum suaveolens, Linum tenuifolium, *Teucrium montanum s.l, Gypsophila collina. Conservation value: high, includes species protected by the state.