The results of the study of algoflora and microfacies from the Lower Carboniferous deposits developed in the Middle and Southern Urals, as well as on the territory of the western slope of the Northern Urals, Novaya Zemlya and the Tyumen-Kustanai trough are presented. The composition of algal associations in the stratigraphic interval from the Kizelovsky horizon of the Tournaisian stage to the Serpukhovian stage, inclusive, is considered and analyzed. The dependence of the composition of algoflora complexes on the facies features of sedimentation environments has been established. The geographic and stratigraphic distribution of a number of genera and species has been specified. The possibility of determining the boundaries of the Lower Carboniferous longline subdivisions and their correlation by the change of characteristic algal complexes is shown. A detailed description of the sections is accompanied by phototables of algoflora complexes and algal microfacies. One new genus and seven new species of green algae are described. The book is addressed to paleontologists, stratigraphers, geologists - generalists, teachers and students of geological departments of universities, attending the course of the discipline “Fundamentals of paleontology. General stratigraphy.