Objective:To improve the capability of ultrasound-guided fine-needle aspiration biopsy (US-FNAB) in diagnosing thyroid diseases. Methods:Total 1 016 US-FNAB cytopathological cases were analyzed retrospectively from May 2011 to Jan 2012 in Department of Endocrinology,the First Affiliated Hospital of NJMU. Meantime,44 histological pathological reports from these patients were analyzed. Results:Among 1 016 US-FNAB cytopathological reports,72 cases (7.09%) were labelled as malignant or suspicious for malignancy while confirmative cytopathological diagnosis for capsula glandulae thyroideae,chronic lymphocytic thyroiditis (CLT) and subacute thyroiditis were seen in 132 (12.99%),165 (16.24%),and 56 (5.51%) cases. By combining cytological result of US-FNAB and histological pathological results of sugery,the sensitivity,specificity,positive predictive value,negative predictive value,false positive rate and false negative rate were calculated as following 65.22%,76.19%,75.00%,66.67%,25.00% and 33.33%. Total positive cell rate was 85.24%. Conclusion:US-FNAB showed great importance in differentiation between benign and malignant thyroid lesions and in diagnosing capsula glandulae thyroideae,chronic lymphocytic thyroiditis and subacute thyroiditis.