Objective：To investigate value of contrast-enhanced ultrasound（CEUS） in differential diagnosis of benign and malignant thyroid nodules. Methods：Dynamic contrast infusion process of 184 thyroid nodules was retrospectively observed in comparison with adjacent thyroid parenchyma. Evaluation criterions were as follows：the time and the pattern of contrast up-take，contrast intensity，time of peak，contrast-enhancement distribution（homogeneous or inhomogeneous），well-defined or not，ring enhancement or not，contrast wash-out early or not. Results：There were statistically significant differences in enhancement patterns between benign and malignant nodules（P<0.001）. Most benign thyroid nodules in CEUS showed synchronal，homogeneous isoenhancement or hyperenhancement and ring enhancement. While most malignant ones showed centripetal and heterogeneous hypoenhancement，contrast up-take latter but earlier diffusion mode. Among all evaluation criterions，early diffusion had the highest sensitivity（92.2%），and up-take latter，cen－tripetal，hypoenhancement had high specificity. Conclusions：Analysis of enhancement patterns is valuable in differential diagnosis of benign and malignant thyroid nodules. Contrast up-take latter，centripetal enhancement，heterogeneous hypoenhancement and earlier diffusion help the diagnosis of malignant thyroid nodules while ring enhancement helps the diagnosis of benign ones.