Objective:To evaluate the effectiveness and safety of the mobilization of peripheral blood hematopoietic stem cells by combining docetaxel with granulocvte colonv-stimulating factor(G-CSF)in breast cancer Patients.metnoos:A total of 57 breast cancer Patients were treated with docetaxel 120 mg/m2.When the white blood cell(WBC)count decreased to 1.0 X10~9/L,patients were given G-CSF 5μg/kg daily by subcutaneous injection until the end of apheresis.Peripheral blood mononuclear cells(MNC)were isolated by Cabe Spectra Apheresis System.The percentage of CD34+ cell was assayed by flow cytometry.Results:At a median 6 of days(range 3-8)after the administration of docetaxel.the median WBC count aecreasea to 1.08x10~9/L(range 0.20-2.31).The median duration of G-CSF mobilization was 3 days(range 2-7).The MNC collection was conducted 8-12 days(median 10 days)after docetaxel treatment.The median MNC was 5.35x10~8/kg(range 0.59-14.07),the median CD34+ cell count was 2.43x10~6/kg(range 0.16-16.69).The CD34+ cellcount was higher than 1.00x10~6/kg in 47 of 57 cases(82.46%)and higher than 2.00x10~6/kg in 36 cases(63.16%).The CD34+ cell count was higher than 2.00x100/kg in 27 collections(23.68%).The MNC count and the CD34+ cellcount were correlated with the bottom of WBC after docetaxel chemotherapy(r=0.364,0.502,P=0.005,0.000).The CD34 cell count was correlated with the MNC count(r=0.597,P=0.000)The mobilization and apheresis were well tolerated in all patients.Mild perioral numbness and numbness of hand or feet were observed in 3 cases.No serious adverse events were reported.Conclusion:Mobilization of peripheral blood hematopoietic stem cell by combining docetaxel with G-CSF was effective and safety in breast cancer patients.