Evolution of polarization state is described by new mathematics, namely, by angular variables technique (AVT) which describes behavior of the angular parameters of polarization ellipse in magnetized plasma. From this point of view the polarization of electromagnetic waves in magnetized plasma is studied in conditions, when Cotton-Mouton effect is weak enough as compared with Faraday one. The method of consequent approximations is applied, which uses the ratio of Cotton-Mouton , and Faraday 3 parameters, as a small parameter of a problem and allows obtaining simple analytical expressions for ellipticity angles approximations