Abstract: Objective To inhibit the expression of VEGF-C gene in human esophageal carcinoma cells EC9706 by siRNA. Methods Three siRNAs targeting VEGF-C were designed. Corresponding expression vectors were constructed and transformed into EC9706 cells. After selection, the stable transfected cells were obtained. VEGF-C mRNA in the stable transfected cells was analyzed by RT-PCR and in situ hybridization. Expression of VEGF-C protein in these cells was analyzed by immunohistochemistry (IHC) method. Stable transfected cells were transplanted into nude mice later. Expression of VEGF-C protein was detected with IHC method in transplanted tumor. Results SiRNA-VEGF-C can decrease the expression of VEGF-C mRNA and protein in EC9706 cells effectively. There were lots of positive granules and positive bands in untransfected EC9706 cells and in the transfection group cells with transfected not-matching any known human coding siRNA. There were few positive granules and week positive bands in transfection group cells with transfected by VEGF-C-targeted siRNA. There were significant differences between transfected and untransfected groups (P<0.01). All the three siRNAs targeting VEGF-C could be the tumorgenesis of EC9706 cells in nude mice. Correspondingly, expressions of VEGF-C protein in xenografts tumors were also reduced. There were significant differences between them (P<0.01). Conclusion siRNAs targeting VEGF-C can inhibit VEGF-C expression effectively in vivo and in vitro. These maybe contribute to the gene therapy of cancer treatment in human esophageal carcinoma.