The main representations of statistical physics of conformational properties of polymer systems are presented. Along with the fundamental concepts of the statistical theory of macromolecules (ideal chain, entropy elasticity, volumetric interactions), much attention is paid to the latest achievements in this area (scaling theory, the idea of ​ ​ reptations, the theory of tangle-globule transition). Applications of statistical theory of macromolecules in biopolymer physics are considered.