【Abstract】 Objective To investigate the expression levels of miR-221, miR-222 and miR-146b in papillary thyroid carcinoma (PTC) of patients in Inner Mongolia, and explore its clinical significance in the diagnosis of PTC. Methods 40 patients with PTC were enrolled in General Surgery Department of The Affiliated Hospital of Inner Mongolia Medical University. The expression of miR-221, miR-222 and miR-146b in carcinoma were detected by reverse transcription polymerase chain reaction and real-time fluorescence quantitative PCR. The relationship between the expression of miR-221, miR-222 ,miR-146b and the clinical characteristics of PTC was analyzed. ROC curve and logistic regression were used to analyze the clinical diagnostic value of miR-221, miR-222 and miR-146b in PTC. Results The expression levels of miR- 221 ,miR-222 and miR-146b in PTC tissues were (2. 282± 0. 679) , (2. 525 ± 0. 785)and(8. 680± 0. 3. 306) , respectively, which were higher than that in the tumor adjacent tissues. The expression of miR-222 was related to tumor size (P＜ 0. 05) , and the expression of miR-146b was related to the age of diagnosis, tumor size and clinical stage (P＜0. 05). The ROC curves AUC of miR-221, miR-222 and miR-146b were 0. 966, 0. 972 and 1. 000, respectively. The sensitivity and specificity of miR-146b in the diagnosis of PTC were 95. 0% and 100%. Conclusion miR-146b may be a potential diagnostic and therapeutic target for PTC patients in Inner Mongolia.