Abstract: Objective To study KLF17 protein expression in esophageal squamous carcinoma and their relationship between clinical and pathological factors；To investigate effect on migration and invasion of Eca109 cells caused by KLF17. Methods KLF17 protein expression in esophageal squamous carcinoma and pericarcinoma normal tissues were detected by immunohistochemical stain.To built carrier of KLF17-lentivirus which infect Eca109 cells and divided cells into three groups called CON、Ad-GFP and Ad-KLF17；KLF17 mRNA expression was detected by real-time PCR；KLF17、E-cadherin、N-cadherin protein expression were detected by Western blot；Migrative ability were observed by wound-healing assay；invasive capacity were observed by transwell assay.Result The rate of KLF17 negative was positively related to infiltration depth，lymph node metastasis and TNM stages（P＜0.05）；KLF17 and E-cadherin protein expression in Ad-KLF17 group were increased significantly than others while N-cadherin protein expression was on the contrary after infection.The migration distance of Ad-KLF17 group was remarkblely shorter than Ad-GFP group and CON group. Transwell assay showed the cells number of Ad-KLF17 group were remarkably less than Ad-GFP group and CON group. Conclusion KLF17 plays a important role in esophageal squamous carcinoma associated with accurrence and progression；EMT could be inhabited in Eca109 cells by KLF17，associated with their migrative and invasive capacity.

Key words: KLF17，esophageal squamous carcinoma，Eca109 cells，EMT.