Research results of hepatoprotective and preventive properties of preparations organic and semiorganic selenium in comparison with selenite of sodium and seled are presented. Methods of clinical, hematological, pathoanatomical, biochemical, statistical research are used. Results of preparations of selenium in preventive dozes have not rendered negative influence on morphological and biochemical parameters of blood. Expressed hepatoprotective effect is revealed at use A-E-Se and selenopiran, that specifies prospect of their application for preventive maintenance of toxic hepatitis at domestic and farm animals