Abstract-Cytokine-induced killer (CIK) cells are T effector cells generated by monocytes cultured and stimulated by cytokines. CIK cells were studied for more than 20 years ago. They can cause lysis of tumor cells that of both autologous and allogeneic origins, so that they were used in cancer treatment. This review aimed to summarize advancements of CIK cells and their current clinical applications in cancer treatment. In general, CIK cells were widely clinically used for recent 5 years. They gave promising results in hepatocellular carcinoma, lung cancer, breast cancer, renal cancer, and treatment. Looking into the future, CIK cell based immunotherapy will become an important tool in cancer treatment.