The activity of species-specific and type-specific antigens in various preparations isolated from the bacterial mass of standard strains of Erysipelothrix, and also in bacterial cells was studied by means of prepared erysipeloid erythrocyte antigen (species-specific and with general type- and species-specificity) and antibody (species-specific, with general type- and species-specificity as also with type-specificity only) diagnosticums. It has been demonstrated that the activity of these antigens differs in preparations from different strains, depending on the method of extraction. An efficient method of serotyping of Erysipelothrix, based on agglutination of erythrocyte antibody diagnosticums, was proposed.