ObjectiveTo investigate expressions and biological function of membrane type matrix metallopro-teinase-1 (MT1-MMP) and matrix metalloproteinase-2 (MMP-2) in papillary thyroid carcinoma. MethodsThe expre-ssions of MT1-MMP and MMP-2 in 164 cases of papillary thyroid carcinoma and paracancerous tissues were detected by immunohistochemistry.The association between the expressions of MT1-MMP and MMP-2 and clinicopathological characteristics of papillary thyroid carcinoma was analyzed. ResultsIn paracancerous tissues, the positive expression rate of MT1-MMP was 11.0% (18/164), and the positive expression rate of MMP-2 was 14.0% (23/164).In papillary thyroid carcinoma tissues, the positive expression rates of MT1-MMP and MMP-2 was 61.6% (101/164) and 67.7% (111/164), respectively.The expressions of MT1-MMP and MMP-2 in carcinoma tissues and para carcinoma tissues were statistically significant differences (P < 0.05).The expressions of MT1-MMP and MMP-2 in papillary thyroid carcinoma tissues correlated with the lymph node metastasis (P < 0.05).In addition, the expression of MMP-2 in papillary thyroid carcinoma tissues correlated with capsule invasion (P < 0.05).The positive correlation was found between the expressions of MT1-MMP and MMP-2 in papillary thyroid carcinoma tissues (r=0.256, P < 0.05). ConclusionsMT1-MMP and MMP-2 may be involved the thyroid capsule invasion and lymph node metastasis of papillary thyroid carcinoma.MT1-MMP and MMP-2 may be involved in the progression of papillary thyroid carcinoma.