Objective:To investigate expression and significance of PRL-3 in thyroid papillary carcinoma and its relationship with clinicopathologic features. Methods:The expression of PRL-3 in primary thyroid papillary carcinoma,the adjacent non-tumor tissues and lymph node metastasis of the thyroid papillary cancer(LMNs) were detected by Real-time PCR and SP immunohistochemistry. Results:The transcription expression of PRL-3 mRNA was higher in primary thyroid papillary carcinoma or LMNs than in the adjacent non-tumor tissues(P < 0.05) .The positive expression rates of PRL-3 were also higher in primary thyroid papillary carcinoma and LMNs than in the adjacent non-tumor tissues(P < 0.05). The positive rates of PRL-3 protein were higher in primary thyroid papillary carcinoma with lymph node metastasis than in primary thyroid papillary carcinoma without lymph node metastasis(P < 0.05). The positive rates of PRL-3 were higher in tumor of size > 2 cm than in tumor of size≤2 cm (P < 0.05).Conclusion:The expression of PRL-3 is closely related to the tumor size and lymph node metastasis. The high expression of PRL-3 in PTC may forecast the lymph node metastasis,and it may be a molecular marker to predict lymph node metastasis in papillary thyroid carcinoma.