The influence of transplantable tumour on migration, proliferation and differentiation of haemopoietic stem cells was studied. It is shown that in the initial period of tumour development the migration and proliferation of stem cells intensify. In the final stage of the tumour growth the quantity of haemopoietic stem cells decreases considerably in the bone marrow, spleen, and peripheral blood. It is established that during the tumour growth the differentiation of stem cells from the spleen changed towards erythropoiesis.