Objective:To investigate the effect of CD137 signal on regulation of CIK cell proliferation and function. Methods:CIK cells were induced from peripheral blood mononuclear cells in the culture with the presence of CD3mAb,IL-2,IFN-γ. Cells treated with CD137mAb or mouse IgG1 isotype control was assigned to experimental group or control group,separately. The cell proliferation was determined by cell counting with trypan blue staining test. Phenotypes and IFN-γ production of CIK cells were analyzed by flow cytometry(FCM);Cytotoxicity was measured by LDH activity released from the supernatant of cell cultures. Results:The concentration of CD137-CIK cells in experimental group was dramatically higher than traditional CIK cells in control group. The concentration was respectively arrived at (9.87 ± 0.57)×106/ml and (7.02 ± 0.68)×106/ml;The percentages of CD3+CD56+ cells and the expression of IFN-γ in experimental group were increased significantly compared with control group as well;The CD137-CIK cells possessed much higher ability to kill lung cancer cell(A549) than IgG1-CIK cells did. Conclusion:CD137-CIK cells exhibited strong activities of proliferation and cytotoxicity against A549 cells.