【Abstract】 Objective To analyze and discuss the expression of miRNA in different pathological types and stages of thyroid carcinoma, and provide reference for the clinical operation and postoperative treatment. Methods 40 patients of thyroid carcinoma (including 20 cases of papillary carcinoma) were collected from people's Hospital of Inner Mongolia Autonomous region and affiliated Hospital of Inner Mongolia Medical University. 20 cases of follicular carcinoma) and 20 cases of benign thyroid disease tissues were collected during operation. After being stored in liquid nitrogen immediately, it was transferred to70 ℃ for storage. The quantitative RTPCR was used to detect miR221 and miR222. The expression level of miR197 and miR346 in corresponding tissues.Results For thyroid cancer, miR221 and miR222 expression and patient age and gender, had no significant correlation between the maximum tumor foci. They were correlated with TNM staging (P＜005) and lymph node metastasis (P＜005). miR197 and miR346 expression significantly increased in thyroid follicular carcinoma (P＜005). The expression of miR221 and miR222 in benign thyroid diseases did not change significantly (P＞005). However, there was a significant change in the expression of PTNE in thyroid carcinoma, There was a negative correlation between them and the expression of PTNE (P＜ 005). The difference was statistically significant (P＜ 005). The expression levels of miR197 and miR346 in corresponding tissues were compared. There was no significant change in the expression of miR197 and miR346 in benign thyroid diseases. In thyroid carcinomas 2 There was a significant increase in 0 cases of follicular carcinoma, the difference was statistically significant (P＜ 005), and there was no significant change in the tissues of papillary carcinoma and normal tissues adjacent to the carcinoma.Conclusion The expression of miRNA in different pathological types and stages of thyroid carcinoma is closely related to early diagnosis, lymph node metastasis, recurrence and distant metastasis of thyroid carcinoma.