Abstract: Objective 　To study the localization and expression levels of MTA1 protein in esophageal squamous cell carcinoma and the relationship between MTA1 expression and the development and metastasis of esophageal squamous cell carcinoma. Methods Immunohistochemistry staining was adopted in tissue array analysis. Results 　MTA1 was located mainly in the nucleus in the primary esophageal squamous cell carcinomas, but in the cells from metastatic carcinoma, the cytoplasmic staining of MTA1 protein located in mucleus and cytoplasm. The difference between normal esophageal squamous cells and dysphasia cells, invasive carcinoma cells was significant ( P < 0. 01) . With the development of esophageal squamous cell carcinoma, the MTA1 expression increased with ectopic location. Conclusion 　There is a st rong relationship between MTA1 overexpression and invasion metastasis of esophageal squamous cell carcinoma, indicating an important role of MTA1 in the development of esophageal squamous cell carcinoma. The MTA1 deregulation may be an accessory indicator for assessing the invasive and metastatic potential of esophageal squamous cell carcinomas.