An approach to the quantitative analysis of the effect of the chemical structure of linear and network polymers on their properties is described. The approach is based on the representation of the repeating unit of the polymer in the form of a set of anharmonic oscillators which describe the thermal motion of atoms in the field of intra- and intermolecular forces, including weak dispersion forces, dipole dipole interactions, hydrogen and valency bonds. Computer programs based on this approach are also presented. They can be used for calculating more than 50 fundamental physical and chemical constants of linear and network polymers as well as low molecular liquids.