Abstract: ObjectiveTo investigate the specific antitumor mechanism of socs1 silent DC and discuss the prospect of RNAi in the gene therapy for laryngocarcinoma in order to provide novel ideas of DC 's clinical applications. MethodsDendritic cells derived from peripheral blood monocytes were cultured in vitro in the presence of GM-CSF,IL-4 and TNF-α. Construct the RNAi vector and transfect it into DC. The expression of SOCS1 was analyzed by Western blot. The alterations of surface markers on mature DC,including CD83,CD86 and HLA-DR,were detected by flow cytometry. The specific killing activity of CTL induced by DC was evaluated by MTT assay. ResultsDendritic cells were obtained successfully. The expression of SOCS1 decreased significantly under the influence of the 5th interference sequence. socs1 silent dendritic cells which were loaded with Hep-2 antigen had high expressions of CD83,CD86 and HLA-DR. It could also enhance the specific killing effect of CTL. The killing activity was significantly higher than control group when the effect cells and target cells were mixed up at the ratio of 50：1(P<0.01). Conclusionsocs1 silent dendritic cells which were loaded with Hep-2 antigen could induce effective and specific anti-laryngocarcinoma immune responses.