Abstract: Objective: To investigate the changes of lymphocyte subsets and CD34⁺ cells in the peripheral blood（PB） of patients with hematological malignancy mobilized with rhG-CSF. Methods: In order get enough peripheral blood progenitor/stem cells,38 patients with leukaemia or lymphoma were mobilized with high-dose chemotherapy and middle-dose rhG-CSF.The lymphocyte subsets（include CD3,CD4,CD8,CD19,and NK cell） and CD34⁺ cells in the PB before and after mobilization were analyzed with flow cytometry.Meanwhile we culture CFU-GM ability in methyl cellulose（MC）semisolid culture medium to（observe） stem cells’ quality. Results: The ratio of CD3,CD4 in monucear cells were obviously deceased after mobilization（（P＜0.01）,P＜0.01）.While CD34⁺ cells in PB increased significantly after mobilization（P＜0.05）,it reached the peak on day 5.CD4/CD8 ratio is inverted seriously. Conclusion: High dose chemotherapy and rhG-CSF have markedly effect on mobilization of the peripheral blood hematopoietic cells（PBPCs） and shift the lymphocyte subsets.