【Abstract】ObjectiveTo study the expressions of matrix metalloproteinase 2 (MMP2) and carbohydrate antigen 50 (CA50) in colorectal carcinoma, cancer-adjacent mucosa （2 cm from the nether edge of tumor）, cancerdistant mucosa （5 cm from the nether edge of tumor） and normal colorectal mucosa, and to elucidate their effects on the development of colorectal carcinoma. MethodsThe expressions of MMP2 and CA50 were detected immunohistochemically in 40 cases of colorectal carcinoma, cancer-adjacent mucosa, cancer-distant mucosa and 10 cases of normal colorectal mucosa. Results①The expression intensity and positive rates of MMP-2 and CA50 increased significantly in turn by normal mucosa, cancer-distant mucosa, cancer-adjacent mucosa and colorectal carcinoma. ②The expression of MMP2 was correlated with CA50 in colorectal carcinoma. ③The expression of CA50 in colorectal carcinoma was closely associated with tumor differentiation, and the expression of MMP2 in colorectal carcinoma was closely associated with differentiation and Dukes stages as well. ConclusionOver expression of MMP2 facilitates the malignant progress of colorectal carcinoma; CA50 is a reliable marker of malignance in colorectal carcinoma; CA50 and MMP2 may have synergetic effects on the development of colorectal carcinoma.