Solid tumour cells show a resistance to immunological effector cells in vitro .1 The resistance may be one reason why these tumours withstand immunotherapeutic approaches in humans. Dendritic cells (DC) play an important role in the immune response to tumour associated antigens in humans. DC in the periphery capture and process antigens, express lymphocyte costimulatory molecules, migrate to lymphoid organs and secrete cytokines to initiate immune response. Cytokine-induced killer (CIK) cells are the major histocompatibility complex-unrestricted cytotoxic lymphocytes and generated from peripheral blood monocytes (PBMC) by a cytokines including anti-CD3 monoclonal antibody, interleukin-2 (IL-2) and interferon-gamma.2 CIK cells are the population of heterogeneous effector cells which possess an enhanced cytotoxicity and a higher proliferation rate than lymphokine-activated killer (LAK) and tumour infiltrating lymphocyte (TIL) cells. The higher antitumour activity of CIK cells is mainly due to the high proliferation of CD3 and CD 56 double-positive cells.3 Some reports indicated that CIK cells can be efficiently employed as an adjuvant in anticancer immunotherapeutic strategy for the eradication of residual cancer cells and prevention or delay of tumour relapse.4 In this study, we tested the changes of CIK cells (after coculturing with tumour antigen pulsed and unpulsed DC) in phenotype, proliferative activity and cytotoxicity, and determined the feasibility of treatment with dendritic cells and CIK cells for lung haematogenous metastasis of colon cancer in BALB/c nude mice. Solid tumor cells show a resistance to immunological effector cells in vitro. 1 The resistance may be one reason why these tumors withstand immunotherapeutic approaches in humans. Dendritic cells (DC) play an important role in the immune response to tumor associated immungens in humans. DC in the periphery capture and process antigens, express lymphocyte costimulatory molecules, migrate to lymphoid organs and secrete cytokines to secrete cytokines to cytokine immune responses. Cytokine-induced killer (CIK) cells are the major histocompatibility complex-unrestricted cytotoxic lymphocytes and generated from peripheral blood monocytes ) by a cytokines including anti-CD3 monoclonal antibody, interleukin-2 (IL-2) and interferon-gamma.2 CIK cells are the population of heterogeneous effector cells which possess an enhanced cytotoxicity and a higher proliferation rate than lymphokine-activated killer (LAK) and tumor infiltrating lymphocyte (TIL) cells. The higher antitumor activity of CIK cells is mainl y due to the high proliferation of CD3 and CD 56 double-positive cells.3 Some reports indicated that CIK cells can be efficiently employed as an adjuvant in anticancer immunotherapeutic strategies for the eradication of residual cancer cells and prevention or delay of tumor relapse.4 In this study, we tested the changes of CIK cells (after coculturing with tumor antigen pulsed and unpulsed DC) in phenotype, proliferative activity and cytotoxicity, and determined the feasibility of treatment with dendritic cells and CIK cells for lung haematogenous metastasis of colon cancer in BALB / c nude mice.