In recent years, the clinical trials on applying cytokine induced killer (CIK) cells to solid tumor therapy have been launched worldwide. CIK cells are a heterogeneous subset of ex-vivo expanded T lymphocytes, they present a mixed T-NK phenotype and are endowed with a MHC-unrestricted antitumor activity, which have showed great advantages in clinical treatment compared with other adoptive immunity therapies, therefore, they are more and more widely used in adoptive immunotherapy of tumors. CIK cells can be used alone or in combination with surgery radiotherapy and chemotherapy for comprehensive treatment. In the present article, we keep a track of research progress both home and abroad, review the main functional characteristics of CIK cells, briefly introduce the source phenotype activation and amplification of the CIK cells, and summarize their targeting and anti-tumor mechanisms new techniques and methods and current status of international clinical trials from several aspects.