Abstract: Objective To study the clinical significance of thyroid hormone receptor β1（TRβ1） expression in thyroid papillary carcinoma and its adjacent and proliferating tissue. Methods TRβ1 protein expression in tissues of thyroid papillary carcinoma patients（201 with thyroid papillary carcinoma and 25 with benign proliferating thyroid papillary carcinoma） was detected by S-P immunohistochemistry. Results The positive TRβ1 expression rate was significantly lower in thyroid papillary carcinoma than in its adjacent and proliferating tissue（12.4% vs 99.5% and 92.0%,P＜0.01）. Conclusion TRβ1 expression rate is significantly lower in thyroid papillary carcinoma than in its adjacent and proliferating tissue,and can thus be used as a molecular marker for the diagnosis of benign and malignant thyroid papillary structure.