Abstract: Objective To investigate the specific cytotoxic T lymphocyte（CTL） immunoreaction of choronic myelocytic leukemia-dendritic cells(CML-DC) transfected with CML total RNA in vitro, and to provide a theoretic basis of CML vaccine in clinical study. Methods Bone marrow mononuclear cells (BMMNCs)from 10 cases of chronic myeloid leukemia were used. BMMNCs were incubated with recombined human interleukin-4 (rhIL-4), recombined with human granulocyte/ macrophage colony-stimulating-factor(rhGM-CSF) and tumor necrosis factor–α(TNF-α).Using Trizol method was used to extract CML-BMMNCs total RNA, and CML-BMMNCs were applied to prepare tumor frozen-thawed antigen. At the 5th day of culture, CML-DCs were divided into four groups: CML-DCs pulsed with total RNA-lipofectamin; CML-DCs pulsed with total RNA; CML-DCs pulsed with tumor frozen-thawed antigen and CML-DCs pulsed with nothing. All of them could induce T cells into specific CTL. T cells cultured with IL-2 served as normal control group. The morphological features of DCs were observed under an inverted microscope. The CD_1α and CD₈₃ were analyzed by flow cytometry. Karyotypes of CML-DC were tested by G-banding technique. The Bcr-abl expression in CML-DCs was detected by reversed transcription polymerase chain reaction (RT-PCR). MTT assay was used to test the capacity of CML-DCs for mixed leukocyte reaction(MLR). Results CML-BMMNCs could be induced into CML-DCs. The expression levels of CD_1α and CD₈₃ in CML-DCs were increased obviously as compared with those in uncultured CML-BMMNCs. Bcr-abl and Ph chromosome all exsisted in cultured CML-DCs and uncultured CML-BMMNCs. It was suggested that CML-DCs were from CML cells. The cytotoxic rate of CML-DCs pulsed with total RNA-lipofectamin, CML-DCs pulsed with total RNA, CML-DCs pulsed with tumor frozen-thawed antigen, CML-DCs pulsed with nothing, and T cells cultured with IL-2 was decreased in turn. Conclusion CML-BMMNCs-derived DCs Being incubated recombined with IL-4，GM-CSF and TNF-α, CML-BMMNCs could be induced into CML-DC. CD_1α and CD₈₃ pressions all increased obviously. The CML-DCs could induce the CTL to get specific anti-tumor activity in vitroThe cytotoxicity of CTL induced by CML-DCs pulsed with total RNA-lipofectamin was the most significant.