Abstract: Objective: To investigate the induction of antitumor immune response of tumor cell lysate sensitized interleukin 18 gene-modified DC. Methods： The mice bone marrow-derived dendritic cells cultured in vitro were transfected by IL-18 recombinant adenovirus, and then were sensitized by hepatoma Hepal-6 cells lysate, and then were used to therapy of tumor-bearing mice in subcutaneous injection. Cytokines were assayed by ELISA, and NK cells and CTL activity were detected by 4h 51Cr releasing assay. Results： There was no difference between the sensitized group IL18-DC and the unsensitized group IL18-DC in the induction of NK cells activity (8>0.05), but NK cells activity of the sensitized group IL18-DC was significantly higher than the sensitized DC group and DC group(8<0.01). The immunotherapy effect of the sensitized group IL18-DC was significantly higher than the unsensitized IL18-DC group, the sensitized DC group and DC group, respectively(8<0.01). Conclusion: Tumor cell lysate sensitized interleukin 18 gene-modified DC could elicit potent antitumor responses in vivo, which will provide a new approach to the DC-mediated gene therapy for tumor.