Abstract: In the eastern highlands of the Lower Caucasus screes and rocks are the landscape of vegetation. They take about one third part of the total highland territory. We have determined the type composition of petrophits and objective laws of their geographical spreading. Studying of the highlands primary-naked substrata is usually carried out beginning with investigation of the highland vegetation. On the screes and rocks 2500-3200 m. higher sea level, floral composition consists of 183 flourishing species. Special edaphic and microclimatic conditions of the screes and rocks made it possible to save there lots of species of the past climatic time.