The book outlines the theoretical methods of high-pressure physics. The main attention is paid to the equations of the state of solids to pressures of several megabars. The equations of state of many metals, ionic crystals, minerals and rocks are given. Questions are considered about the effect of pressure on the parameter. Gruneisen, anharmonicity, diffusion, thermal ionization and melting curves. The book contains special chapters devoted to the definition of state equations for dynamic, shock data, as well as theoretical methods for determining state equations for ionic and molecular crystals. Examples of the use of high-pressure physics methods for the study of the earth's interior. The book contains a lot of original material, previously unpublished . It will be useful to all specialists who are somehow involved with high-pressure physics, astrophysics, geophysics and planetary physics. It can be recommended as a manual for senior students of universities and engineering and physical institutes specializing in high pressure physics, high temperature physics and mechanical properties of materials.