Abstract: To explore the potential ex vivo expansion ability of the human bone marrow mononuclear cells(MNCs) and AC133＋ selection cells under different cell factor combination stimulation. Methods: This research utilizes the Ficoll to separate human bone marrow MNCs and MiniMACS to gather AC133＋cells. The cell factors were divided into 6 groups. Through the ex vivo comparison cultivation under different cell factor combination stimulation, the expansion and AC133 phenotype of MNCs and AC133＋ selection cells were observed, and the clone formation of the MNCs and AC133＋ selection cells under different cell factor stimulation on different time was observed by using Halfsolid Methyl cellulose. Results: In the same condition, human bone marrow MNCs were expanding much more than AC133＋ cells, and their clone density was more than AC133＋ selection cells（P＜0.05）. In cell factor combination 6 stimulation, human bone marrow MNCs and AC133＋ selection cells were expanding much more than other cell factor combinations （P＜0.05）, and the clone density generated by cell factor combination 6 highered than the clone density generated by other combination stimulations under the same conditions（P＜0.05）. Conclusion: Through the 4week shortterm cultivation, human MNCs are generating more stem cells. Cell factor combination 6 is the first choice for ex vivo expansion.

Key words: Hematopoietic stem cell, Bone marrow, Persons, Mononuclear cells, AC133＋ selection cells,