Objective To separate and cultivate homo umbilical cord blood (UCB) hematopoietic stem cell (HSC) in vitro, and u-tilize bone marrow desmohemoblast stem cell as trophoblastic layer combined with cytokine to amplify umbilical cord blood hematopoietic stem/progenitor cell. Methods Ficoll lymph-cell separating medium density gradient centrifugalization was used to segregate UCBHSC.Bone marrow desmohemoblast stem ceil and cytokine were added, and the sum of NC cells and CD34 + cells was counted. Results The sum of NC cells amplified 75.2±15.0 times, and the sum of CD 34 + cells amplified 18.7±12.3 times. Conclusions It has significant effect on amplification of hematopoietic stem cell with bone marrow desmohemoblast stem cell and eytokine when HSC are cultured in vitro.