The advances in transplantation of hemopoietic stem cells (HSC) from umbilical human blood (UHB) necessitate introduction of effective methods of HSC isolation and preservation. The studies show that UHB cells remained viable even after several days of storage at room temperature. Density gradients proved effective for isolation of cell precursors from UHB. Most of hemopoietic cell-precursors in UHB have low density (under 1.070 g/ml) which becomes greater with cell maturation.