Abstract: ObjectiveTo study the expression of PEBP4 in esophageal cancer,and relationship between PEBP4 and the clinical pathologic features of esophageal cancer,and the function of PEBP4 in invasion and metastasis.MethodThe expressions of PEBP4 mRNA and protein were detected using RT-PCR,immunohistochemistry and Western blot in esophageal cancer tissues and peri-cancer tissues.The change in the invasive ability of human esophageal cancer cell line Eca-109 was detected after knocking down PEBP4 expression using RNA interference.ResultThe positive mRNA expression rate of PEBP4 in esophageal cancer tissues was significantly higher than that in peri-cancer tissues(P＜0.05).The positive mRNA expression rate in the carcinoma tissues from patients with positive lymph nodes or distant metastasis was significantly higher than that from patients without lymph nodes or distant metastasis(P＜0.05).However,expression of PEBP4 was independent of gender,age,tumor size,or tumor differentiation level(P＞0.05).The results of PEBP4 protein were similar to the PEBP4 mRNA.Invasion and metastasis of Eca-109 cell might significantly be inhibited through down-regulation of PEBP4 protein(P＜0.01). Conclusion The over-expression of PEBP4 might be related to the carcinogenesis and development as well as metastasis and invasion of esophageal cancer.