Information on geochemistry as an independent direction of geology is given. A brief description of modern methods for studying the composition of rocks and radioisotope geochronology is given. The issues of geochemical classification, migration of chemical elements, factors and forms of their dispersion and concentration are considered. Modern relevant ideas on the geochemistry of the Earth's shells and geological processes are presented. The issues of geochemistry of the noosphere and technogenesis, the practical application of geochemistry are covered.