The textbook is devoted to the basics of polarization optics - a new direction of optics, which has recently been formed due to the rapid development of polarization-optical devices and the use of polarized light in technology, biology and medicine. Basic methods of polarization analysis are described, which make it possible to solve problems of transformation of polarization state by anisotropic optical path taking into account depolarizing factors, as well as to determine polarization characteristics of optical resonators. Polarizers, phase plates, optical rotators, compensators and other polarizing devices are described in detail.