The book describes various representations of the gravitational potential of extended bodies. Minimal information from abstract potential theory is reported. The textbook on the part of the course of celestial mechanics was prepared at the Department of Celestial Mechanics of St. Petersburg State University and is intended for students and graduate students of astronomical and astronomical geodetic departments and departments of universities , as well as for specialists in the field of celestial mechanics, Space Geodesy , gravimetry, Space Flight Theory . The electronic version is posted on the website ''Astronomy at St. Petersburg University'' (http://astro.) pu. ru)