Objective: To observe the killing effect of the cytokine induced killer cells (CIKs) after co-culture with dendritic cells (DCs) harboring K-ras (12-Val) mutant peptide on pancreatic cancer PANC-1 cells. Methods: DCs and CIKs were induced and enriched from peripheral blood of healthy donors, respectively. DCs were loaded with the K-ras mutant epitope peptide (K-ras-DCs), and CIKs were co-cultured with un-loaded DCs or K-ras-DCs to obtain the DC-CIKs and K-ras-DC-CIKs, respectively. The proliferative activities between CIKs and K-ras-DC-CIKs were compared, the difference in immunophenotype between DCs and K-ras-DCs as well as between CIKs and K-ras-DC-CIKs were analyzed, the IFN-γ and IL-12 levels in the culture supernatants from CIKs, DC-CIKs and K-ras-DC-CIKs were measured, and the killing abilities of CIKs, DC-CIKs and K-ras-DC-CIKs on PANC-1 cells in vitro were determined. Results: The proliferative ability of K-ras-DC-CIKs was significantly greater than that of the untreated CIKs (P<0.05); the expressions of the mature surface proteins that included CD1a, CD80, CD83 and HLA-DR in K-ras-DCs were significantly higher than those in un-loaded DCs, while the expression rates of CD3+CD56+ and CD3+CD8+ in K-ras-DC-CIK cell population were significantly higher than those in pure CIK population (all P<0.05); the levels of IFN-γ and IL-12 in the cell culture supernatant, and the killing ability on PANC-1 cells from high to low order were K-ras-DC-CIKs, DC-CIKs, and pure CIKs (all P<0.05). Conclusion: K-ras mutant peptide can promote DCs maturation, and DCs harboring K-ras mutant peptide can increase the proliferation of CIKs and killing effect on pancreatic cancer cells.