Objective:To investigate the expression of human epidermal growth factor receptor 4 (HER4) and metastasis-related protein (MMP-9) in human esophageal carcinoma tissues, and their relationship with clinicopathological features of the disease. Methods:Immunohistochemical Envision technique was applied to detect the expressions of HER4 and MMP-9 in 45 specimens of esophageal carcinoma tissues, paracancerous tissues and normal tissues. Statistical method was used to analyze the association of the positivity of HER4 with clinical pathological index and MMP-9 expression.Results:The positive rates of HER4 expression were 73.3%, 33.3%, and 2.2% in 45 specimens of esophageal carcinoma tissues, paracancerous tissues, and normal tissues, respectively. The expression of HER4 was correlated with TNM stage and lymph node metastasis (P<0.01), but not correlated with histological grade (P>0.05). The expression of MMP-9 correlated with T stage, invasion depth, TNM stage, and lymph node metastasis (P<0.05). Conclusion:The expression of HER4 is apparently different in esophageal carcinoma tissues, paracancerous tissues, and normal tissues. Its positive expression in esophageal carcinoma tissues is correlated with TNM stage and lymph node metastasis. The expression of MMP-9 in esophageal carcinoma tissues is correlated with the T stage, TNM staging, and lymph node metastasis. The positive expression of HER4 in esophageal carcinoma tissues is associated with the expressions of MMP-9.