Objective：To explore the effect of cytokine induced killer（CIK） on the growth and proliferation of liver cancer stem cells （LCSCs）. Methods：LCSCs were prepared from liver cancer cell line SMMC7721 induced by serum-free medium（SFM） containing several cytokines（LIF，EGF，bFGF and B27），and their CD90 and CD133 were identified by flow cytometry（FCM）. Meanwhile，CIK cells were produced from suspended peripheral blood mononuclear cells（PBMCs） of patients with hepatocellular carcinoma（HCC） in－duced by IFN-γ，human CD3 monoclonal antibody（hCD3mAb） and IL-2. LCSCs and CIK were cultured in a same circumstance with a Transwell culturing cabin，but the LCSCs were cultured at one side of the membrane of the Transwell，and the CIK cells were cul－tured at another side of the same membrane for 24 h and 48 h respectively. The effects of CIK cells on the growth and proliferation of LCSCs were detected by cell count kit-8（CCK-8）. The expression of gene and encoding protein of proliferating cell nuclear antigen （PCNA） were assayed via RT-PCR and Western blot respectively. Results：The high expressions of CD90 and CD133 in LCSCs were tested by FCM. The results of CCK-8 indicated that the growth and proliferation of LCSCs co-cultured with the CIK cells were slower than those of control cells，which become more visible at 48 h after co-culturing（P<0.01）. The results of RT-PCR and Western blot revealed that CIK cells can significantly down-regulate the ex－pression of gene and encode protein of PCNA in LCSCs. Con－clusion：LCSCs are induced，cultured and identified successfully. The CIK cells induced from patients with HCC can significantly prevent LCSCs from growth and proliferation and down-regulate the gene and encode protein of PCNA in them.