Abstract: Objective To investigate the killing effect of dendritic cells (DC) and cytokine-induced killer (CIK) cells loaded with gastric cancer stem cell antigens on gastric cancer cells. Methods Human gastric cancer stem cells were isolated and identifi ed. Antigens were made with the freeze-thaw method. The phenotype of DC-CIK cells loaded on gastric cancer stem cells was examined with fl ow cytometry.Gastric cancer cells were cultured in DC group,DC-CIK group,gastric cancer cell antigen group and gastric cancer stem cell antigen group respectively. Methyl thiazolyl tetrazolium (MTT )method was used to examine the killing effect of DCCIK on gastric cancer cells in each group. Results The expression of surface maturity markers CD83 and CD86 of DC cells stimulated by gastric cancer stem cell antigen signifi cantly increased to 80.4%, higher than the DC group, DC-CIK group and gastric cancer cell antigen group(P <0.01). MTT test results showed that the destruction rates of gastric cancer of gastric cancer stem cell antigen group, gastric cancer cell antigen group, DC-CIK group and DC group were (80.6 ± 0.8)%, (72.3 ± 0.6)%, (58.4 ± 0.2)% and (49.7 ± 0.8)% (P <0.01). Conclusion Stimulating DC cells as an antigen, gastric cancer stem cells could enhance the immunoreaction of dendritic cells, promote cell proliferation, and therefore improve killing effect on gastric cancer cells.