Abstract: Objective To investigate the expression of MMP-9 and E-cadherin in early gastric carcinoma and metastasic lymph node to explore the mechanism of gastric carcinogenesis and invasion or metastasis. Methods Immunohistochemical methods were used to detect the expressions of MMP-9 and E-cadherin in 25 cases of early gastric carcinoma and 25 cases of metastastic lymph node from early gastric carcinoma. Results The expression of MMP-9 was significantly correlated with Lauren's classification, LN metastasis and infiltrating depth. The expression of E-cadherin was significantly correlated with differentiation, Lauren's classification, and LN metastasis. There was significant difference between early gastric carcinoma and metastasic lymph node for the expression of MMP-9 and E-cadherin. There was a reverse correlation between MMP-9 and E-cadherin. Conclusion With the tumor progression, the abnormal expressions of MMP-9 or E-cadherin are gradually correspondingly increasing, thus suggesting that they play a crucial role in gastric carcinoma progression and can be objective markers for biological behaviors of early gastric carcinoma. Furthermore, these two factors influence each other and further accelerate the process of tumor progression.