The method of heterotopic transplantation of the bone marrow was used to study the influence of splenectomy and autotransplantation of the spleen onto the hemopoietic and osteogenic tissues of the bone marrow in mice. After splenectomy at early stages of the formation of the heterotopic hemopoiesis focus the amount of myelokaryocytes increased while in the stationary bone marrow population (the femur bone) their amount dropped by the same time. Autotransplantation of the spleen made the amount of myelokaryocytes equal to the level of control, but did not eliminate the effect of decrease of the mass of osteogenic tissue in the heterotopic hemopoiesis focus arising after splenectomy, which might be related with the influence of splenectomy on the stem osteogenic cells-precursors of the bone marrow.