Objective To evaluate the efficiency of thyroid ultrasound grading formulated by American Thyroid Association (ATA) and fine-needle aspiration (FNA) biopsy in diagnosing benign and malignant thyroid nodules.Methods A retrospective analysis of 357 thyroid nodules in 342 patients underwent surgical excision or FNA biopsy after thyroid ultrasound was performed.All ultrasonograms were graded according to ATA diagnosis guideline for thyroid nodule versi on 2015.The diagnostic efficiency of ATA grading and FNA biopsy were evaluated comparing with postoperative pathological results.Results There were 248 of 357 thyroid nodules confirmed with postoperative pathology,including 233 malignant and 15 benign nodules.The diagnostic accuracy,sensitivity,specificity,positive and negative predictive value of ATA guideline in diagnosis of malignant thyroid nodules was 88.31％ (219/248),90.99％ (213/233),46.67％ (7/15),96.36％ (212/220)and 25.00％ (7/28),respectively,while of FNA biopsy was 98.81％ (83/84),100％ (75/75),88.89 ％ (8/9),98.68％ (75/76) and 100％ (8/8),respectively.The area under the curve (AUC) of ROC was 0.653 and 0.944 for ATA grading and FNA biopsy,respectively (Z=2.397,P=0.017).Conclusion ATA guideline has high diagnostic value in differential diagnosis of thyroid nodules,while FNA may be more effective in diagnosis of thyroid nodules.