Immunomodulating properties of the bioginseng preparations (Panax ginseng), isolated from the cell culture of ginseng calluses, were studied in model experiments of acquired immunodeficiency developed as a result of long-term protein starvation or after vinblastin administration. The following preparations were studied: 1) preparation obtained by means of the cell culture cryoconcentration, 2) ethanol extract of the cell culture, 3) high-molecular protein containing fraction of the bioginseng I. Under conditions of acquired immunodeficiency all the preparations studied were shown to increase the content of antibody producing cells developed in response to sheep erythrocytes administration, while the highest effect exhibited the bioginseng preparation III. These data suggest that proteins are of great importance in the immunomodulating effects of bioginseng preparations.