The experiments on 766 albino non-inbred rats and 270 mice BALB/c showed that when there were no basic differences in the mechanism of the anthracycline myeloinhibitory effect associated with a decrease in the number of the exogenic trunk hemopoietic cells, inhibition of the bone marrow proliferative activity and a decreased rate of the hemopoietic elements differentiation, carminomycin induced a more pronounced and persisting impairment of the hematopoietic tissue proliferation, as compared to rubomycin on their administration in doses equivalent by the total toxicity.