Abstract: ObjectiveTo study the efficacy and factors that affect the efficacy of Doctaxel Combined rhG-CSF for peripheral blood stem cell （PBSC）mobilization for patients with breast cancer. MethodsFifty five patients with breast cancer were included in our study. TXT at the dose of 120 mg/m2 was given continuously for 3 hours. When the number of white blood cell was less than 1.0×109/L，rhG-CSF was given until the end of leukopheresis. CD34+ cells collected by a continuous flow cell separator from peripheral blood were analyzed with FACS. Various elements might affecting the yield of CD34+, including age, the lowest number of leucocyte after chemotherapy, the blood cell count before leukopheresis, visceral or bone metastases, prior chemotherapy and radiotherapy, were analyazed. ResultsThe leukopheresis was started on the median 10th day after mobilization chemotherapy. The mean number of MNC and CD34+ cells were (5.51±1.24)×108/kg and(2.90±1.38)×106/kg respectively. The age and the lowest number of leucocyte were related with CD34+ cells number. The CD34+ cells number was higher in patients with the cycles of chemotherapy less than or equal to 6 than that in the matched group（P<0.05）.No serious adverse side effect was observed. ConclusionTXT plus rhG-CSF was an effective and safe mobilization regimen for autologous peripheral blood stem progenitor cells in patients with breast cancer. The age and prior chemotherapy cycles affected the number of CD34+ cells collected. The lowest number of leucocyte may be a good predictor of CD34+ cells collected.