Abstract: Objective Protein profi ling was detected both in cells lysates and culture supernatant of cytokine induced killer (CIK) cells from different patients by protein chip technology. Methods The peripheral blood mononuclear cells (PBMC) of 3 tumor patients were stimulated by different cytokines and induced into CIK cells in vitro. The phenotypes of CIK cells were analyzed by fl ow cytometry. CIK cells and culture supernatant was collected respectively after cultured for 20 days. Expression changes of 507 proteins were detected either in cells lysates or in cell culture supernatant by AAH-BLM-1 protein chip technology. Results The percentages of CD3+ and CD3+CD56+ were （86.43±10.65）% and （38.58±3.94）% respectively after CIK cells expanding for 20 days. Six proteins were increased signifi cantly in cell culture supernatant (signal ≥700, FC≥1.8): MIP - 1 β (FC=21.28), GzmA (FC=5.54), IFN- ? (FC=2.78), MCP - 1 (FC=2.22), TMPO (FC=2.05), IL - 13 (FC=1.81). Eight proteins were increased significantly in cells lysates (signal≥700): GzmA (signal=1,968.77), ET (signal=1,398.60), IL - 13 (signal=1,333.47), TFPI (signal=959.76), NRG3 (signal=944.09), IL - 7 (signal=867.12), MIP - 1α (signal=833.43), MIP - 1β (signal=704.88). Three proteins of GzmA, IL-13 and MIP-1β were increased significantly both in two groups. Conclusion CIK cells synthesize and release a variety of protein products during the process of activation, such as GzmA, IFN-γ, IL-8, IL-13, etc. These proteins play important roles of anti-tumor by killing tumor cells directly / indirectly and promoting the proliferation and activation of T cells.