Objective:To investigate the expression of cyclooxygenase-2 (COX-2) and vascular endothelial growth factor-C (VEGF-C) in papillary thyroid carcinoma and their relationship to cervical lymph metastases.Method:In this study, the expressions of COX-2 and VEGF-C were examined by immunohistochemistry in papillary thyroid carcinoma tissues of 40 patients, and analysis was performed on the correlation of cervical lymph metastases with COX-2 and VEGF-C expression.Result:Positive expressions of COX-2 and VEGF-C were 70.0%(28/40)and 75.0%(30/40)respectively in papillary thyroid carcinoma. The positive rates of COX-2 and VEGF-C expression were 80.8%(21/26)and 84.6%(22/26)respectively in patients with cervical lymph metastases, and 50.0%(7/14)and 57.1%(8/14)respectively in patients without cervical lymph metastases, with a statistically significant difference between two groups(P<0.05, all). COX-2 was positively correlated to VEGF-C expression in papillary thyroid carcinoma(r=0.378, P<0.05).Conclusion:The results suggest that COX-2 and VEGF-C were highly expressed in papillary thyroid carcinoma, with possible interaction of their expressions, and may play a critical role in the cervical lymph metastases of papillary thyroid carcinoma.