Textbook / Moscow: Moscow University Publishing House, 1985. - 25 s. The electronic version is prepared on the basis of the publication: Experimental methods of chemical kinetics: . allowance/ Under. Red. N. M. Emanuel and M. G, Kuzmina . Moscow: Moscow University Press, 1985. - a brief description of the theory of paramagnetism in general and its application in EPR in particular - the processes of spin relaxation are described - the influence of various factors on the shape and width of EPR lines is explained - the ultra-thin structure of EPR spectra is considered - the application of the EPR method in physical kinetics is described briefly about the general principles of the EPR spectrometer