Abstract: Objective To explore the effect of silencing STAT3 by siRNA on expression of MMP-2 in Esophageal Carcinoma cell line EC-1 and to observe the effect of STAT3 on the occurrence, development, invasion and metastasis in esophageal carcinoma. Methods Small interfering RNA (siRNA) targeting STAT3 was transfected into EC-1 cells. The transfecting efficiency was tested under fluorescence microscope. mRNA and protein levels of STAT3 MMP-2 were evaluated by semi-quantitative RT-PCR and Western blot, respectively. Results Both mRNA and protein levels of STAT3 and MMP-2 were down-regulated after the siRNA targeting STAT3 gene were transfected in EC-1 efficiently. Conclusion The siRNA targeting STAT3 gene could efficiently reduce mRNA and protein levels of STAT3 gene and at the same time down-regulated mRNA and protein levels of MMP-2 by attaching to its gene promoter; STAT3 plays an important role on the occurrence, development, invasion and metastasis in esophageal carcinoma and it could become an important gene target in the treatment of esophageal carcinoma.