Objective：To investigate the expression of matrix metalloproteinase-19（MMP-19） in gastric adenocarcinoma，explore its correlation with N-cadherin（N-cad），and analyze its prognostic significance. Methods：In our study，64 patients with gastric adenocar－cinoma of operation were collected as the study objects in the Affiliated Hospital of North China University of Science and Technology. Tumor tissue was taken as the observation group and normal gastric mucosa tissue was taken as the control group. The expression of MMP-19 was detected by immunohistochemistry method in two groups. The expression of N-cad was detected by immunohisto－chemistry method in observation group. Semi quantitative expression of MMP-19 was detected by Western blot in two groups. Gastric cancer cell line MGC803 was selected. We established siMMP-19 group，empty vector transfection group and blank control group. The expression of N-cad was detected by Western blot. Results：The positive rate of MMP-19 was higher in gastric adenocarcinoma than that in normal gastric mucosa（57.8% vs. 23.4%， χ2=15.68，P=0.001） by immunohistochemistry method. The expression of MMP-19 had statistical significance in infiltration depth（57.8% vs. 37.9%， χ2=8.59，P=0.001），tumor thrombus（83.3% vs. 47.80%， χ2=6.69，P=0.010） and lymph node metastasis（27.7% % vs. 47.6%， χ2=5.21，P=0.023）. Expression of MMP-19 was related to survival time by survival analysis（P=0.020）. Positive correlation was found between MMP-19 and N-cad（r=0.62，P=0.013） by Pearson correlation analysis. Semi quantitative expression of MMP-19 was significantly higher in the observation group than that in the control group by Western blot（1.68±0.23 vs. 1.10±0.24， χ2=5.32，P=0.020）. Expression of MMP-19 was lower in siMMP-19 group than that in empty vector transfection group and blank control group. Conclusion：MMP-19 is highly expressed in gastric adeno－carcinoma，and it’s involved in tumor formation and development. In gastric adenocarcinoma，MMP-19 is positively correlated with N-cad. Detection of the expression of MMP-19 in gastric adenocarcinoma may be of certain value in predicting the prognosis.