Background:The aim of this study was to evaluate the efficacy of ultrasonic features in predicting the malignancy of thyroid nodules in a group of Chinese patients.Methods:In all,762 patients with thyroid nodules (424 malignant and 338 benign) underwent ultrasound (US) check and surgery between March 2011 and July 2014 at Peking University First Hospital were identified.Univariate and receiver operating characteristic (ROC)analyses were performed to calculate the sensitivity,specificity,negative and positive predictive values of each US feature,and the accuracy of their combinations for prediction of malignancy.Results:Patients with malignant nodules were younger and without obvious risk history than those in the benign group (P ＜ 0.001,P =0.93).No individual US sign was fully predictive of a malignant lesion.The Youden indexes of irregular margins and hypoechogenicity were the first and second highest in all US features,which were 51.9％ and 45.2％,respectively.The sensitivity of solid components (89.7％) and hypoechogenicity (89.2％) and the specificity of taller-than-wide shape (98.5％) and microcalcifications (90.6％) were the first and second highest in all US features.Intranodular flow on a color Doppler examination was a weak predictor of malignancy.Under ROC analysis excepting intranodular flow,the 95％ confidence interval (CI) of areas under the curves of hypoechogenicity and irregular margins with any one of the US features were overlapped that of five-feature combinations (95％ CI:0.850-0.901).Conclusions:We should be alert with taller-than-wide shape and microcalcifications.lntranodular flow was a weak predictor of malignancy.According to Youden indexes and ROC analysis,irregular margins and hypoechogenicity combined with solid component or taller-than-wide shapes or microcalcifications have a high predicative value for malignant thyroid nodules in Chinese patients.