Fractalkine (FK, also called neurotactin or CX3CL1) is a CX3C chemokine that can chemoattract T lymphocytes, monocytes and NK cells. In our study, we investigated the induction of antitumor response by FK gene transfer. FK gene‐modified 3LL lung carcinoma cells (3LL‐FK) could both secrete soluble form and express membrane‐bound form of FK. The tumor growth of 3LL‐FK was decreased. Vaccination with 3LL‐FK was effective in the induction of protective immunity and CTL. In vivo depletion analysis demonstrated that CD8⁺ T cells are the main participating cells of the antitumor response. Obvious infiltrations of CD8⁺ T cells, CD4⁺ T cells and dendritic cells (DC) were observed in the tumor sites, suggesting that 3LL‐FK might induce antitumor immunity through chemoattraction and activation of T cells and DC. Then we investigated the chemoattraction and activation of DC by 3LL‐FK. Chemotaxis assay showed that the supernatants of 3LL‐FK could chemoattract immature DC, which were found to express FK receptor CX3CR1, and the immature DC could obviously adhere to 3LL‐FK. Adherence of DC to 3LL‐FK resulted in phenotypic maturation and upregulated IL‐12 secretion of DC, and more strong stimulation of allogeneic T‐cell proliferation by DC. The increased production of IL‐2 and IFNγ in 3LL‐FK tumor tissue was also observed. Our data suggested that FK gene transfer to tumor cells could induce T‐cell‐dependent antitumor immunity through chemoattraction and activation of DC. © 2002 Wiley‐Liss, Inc.