Objective: To explore the effects of dentritic cells on the peripheral blood lymphocyte subpopulations of metastatic breast cancer patients treated with chemotherapy. Methods: The current study involved 44 metastatic breast cancer patients treated with docetaxel-based chemotherapy. Among them, 25 cases were treated with dendritic cells derived from CD34+ hematopoietic stem cells enriched autologous peripheral mononuclear cells after chemotherapy, and 19 cases received chemotherapy alone. Peripheral blood samples were collected from each patient before and after treatment, and lymphocyte subpopulations including CD3+, CD3+/CD4+, CD3+/CD8+, CD3-/CD16+56+, CD3+/CD16+56+, CD4+/CD25+, CD8+/CD28-, CD8+/CD28+, CD4/CD8, DC1, DC2 and DC1/DC2 were analysed by a 3-color flow cytometric analysis. Results: The two treatment groups were well matched with regard to demographic and baseline disease characteristics. Comparing the changes of lymphocyte subpopulations between the two groups, it showed that the difference of the change of CD8+/CD28-lymphocyte had statistic significance. The percentage of CD8+/CD28-lymphocyte was lower in the chemotherapy+DC group, but higher in the chemotherapy-alone group. Conclusion: As CD8+/CD28-lymphocyte represent a kind of suppressive T lymphocyte, we conclude that dentritic cell therapy can relieve immunosuppression to some extent. Objective: To explore the effects of dentritic cells on the peripheral blood lymphocyte subpopulations of metastatic breast cancer patients treated with chemotherapy. Methods: The current study involving 44 metastatic breast cancer patients treated with docetaxel-based chemotherapy. Among them, 25 cases were treated with Dendritic cells derived from CD34 + hematopoietic stem cells enriched autologous peripheral mononuclear cells after chemotherapy, and 19 cases of received chemotherapy alone. Peripheral blood samples were collected from each patient before and after treatment, and lymphocyte subpopulations including CD3 +, CD3 + / CD4 +, CD3 + / CD8 + CD3 + / CD16 + 56 +, CD3 + / CD16 + 56 +, CD4 + / CD25 +, CD8 + / CD28-, CD8 + / CD28 +, CD4 / CD8, DC1, DC2 and DC1 / DC2 were analyzed by a 3-color flow cytometric analysis. Results: The two treatment groups were well matched with regard to demographic and baseline disease characteristics. Comparing the changes of lymphocyte subpopulations between the two groups, it showed th at the difference of the change of CD8 + / CD28-lymphocyte had statistic significance. The percentage of CD8 + / CD28-lymphocyte was lower in the chemotherapy + DC group, but higher in the chemotherapy-alone group. represent a kind of suppressive T lymphocyte, we conclude that dentritic cell therapy can relieve immunosuppression to some extent.