To investigate the effect of in vivo rhG-CSF on the CXCR-4 expression of hematopoietic progenitor or stem cells in bone marrow and peripheral blood, the expressions of CXCR-4 on CD34(+) cells and mononuclear cells of bone marrow and peripheral blood from healthy donor before and after mobilization were detected by three-color fluorescence analysis. The results showed that a significantly higher expression of CXCR4 on CD34(+) cells of bone marrow and mononuclear cells of peripheral blood, as compared to those before mobilization. There were no significant differences of CXCR-4 expression of CD34(+) cells in peripheral blood after mobilization, as compared with steady state bone marrow, and no dynamic change of mononuclear cells expressing CXCR-4 in bone marrow before and after mobilization. Significant positive correlation were found between the percentage of CD34(+) cells in bone marrow before mobilization and that in bone marrow and peripheral blood after mobilization; furthermore, the percentage of CD34(+) cells of bone marrow before mobilization had a positive correlation with both the count of CD34(+) cells per kilogram on the day of collection in bone marrow and peripheral blood after mobilization. It is concluded that the mobilization of hematopoietic cells may be involved in the signaling of SDF-1/CXCR-4 according to the increase of the surface expression of CXCR-4 on CD34(+) cells in bone marrow and on the MNC in peripheral blood after mobilization; meanwhile, the high surface expression of CXCR-4 may contribute to the MNC engraftment, monitoring the percentage of CD34(+) cells in bone marrow before mobilization can be regarded as a predictive factor for mobilization outcome.