This is a textbook in the course of Soil Mechanics for higher- school students of civil engineering and hydrotechnical engineering, and also for students of other specialities associated with construc­ tion of engineering structures, such as road constructors, ameliora­ tors, geologists, soil scientists. The Author has made an attempt to write a concise course on the basis of a wide synthesis of natural sciences and to present the theore­ tical data in the most simple and comprehensive form, without depreciating, however, the general scientific aspect of the problem; his other aim was to present a number of engineering solutions of problems in the theory of soil mechanics (calculations of strength, stability and deformability), which might be widely used in engi­ neering. The book is based on the course of lectures given by the Author at the Moscow Civil Engineering Institute, his earlier book (Soil Mechanics, 4th ed., Moscow, Stroiizdat, 1963), and the newest research works in soil mechanics, both Soviet and foreign, and their practical applications. Some problems in the book are discussed from new standpoints which take into account the principal properties of soils: contact shear resistance, structure-phase deformability (including creep of skeleton), compressibility of gas-containing porous water, and the effect of natural compaction of soils. The book shows some new methods used for determination of characteristics of soils and gives some new solutions of the theory of consolidation and creep of soils, which can be used for predictions of settlement rates of foundations of structures and their time varia­ tions; a separate chapter discusses rheological processes in soils and their significance.