Purpose:To study the expression of MT1-MMP ,EMMPRIN and P-gp in gastric carcinoma and the relation of invasion, metastasis with drug resistance in gastric carcinoma. Methods:Detected membrane-type-1 matrix metalloproteinase (MT1-MMP), extra-cellular matrix metalloproteinase inducer (EMMPRIN), P-glycoprotein (P-gp) in gastric carcinoma by immunohistochemical method. Results:Among 40 cases of gastric carcinoma, there were 15 cases (37.5%) MT1-MMP-positive, 26 cases (65%) EMMPRIN-positive, 23 cases (57.5%) P-gp-positive respectively. The over-expression of MT1-MMP, EMMPRIN, P-gp was associated with invasive depth and lymph node matasteses of tumor cells(P