The phenomena accompanying shock polarization of linear dielectrics and depolarization of nonlinear dielectrics are considered. It is established that the appearance of an emf on the front of a shock wave is a characteristic of a large class of substances, such as linear and nonlinear dielectrics, semiconductors, and metals. It is shown that the emf produced by shock compression of ionic crystals, polar dielectrics, semiconductors, and a number of metals is due to shock polarization. Diffusion of carriers from the front of a shock wave is observed in shock-compressed bismuth, europium, and aluminum. Shock compression of polarization nonlinear dielectrics leads to a stronger effect, namely to the onset of a depolarization emf. The presented phenomenological description of shock polarization is in good agreement with experiment.