Objective To explore the diagnostic value of CEUS for thyroid TI-RADS 3,4 nodules.Methods The CEUS performence of 95 patients with thyroid TI-RADS 3,4 nodules (all were confirmed by surgery pathology) diagosed by conventional ultrasound were reviewed retrospectively,and the value of CEUS in the revision and differential diagnosis of thyroid TI-RADS 3,4 nodules were analyzed.Results Compared with pathological pattern,conventional ultrasound TI-RADS classifications in assessing the property of thyroid nodule had no statistical differences (χ2 =3.56,P =0.06).For thyroid TI-RADS 3,4 nodules,compared with conventional ultrasound TI-RADS classifications,the diagnosis accuracy of CEUS score and revised CEUS TI-RADS classifications showed significant differeces respectively (P=0.03,＜0.01) for thyroid papillary carcinoma greater than 1 cm.But no statistical difference were found respectively (P=0.25,1.00) for thyroid papillary carcinoma smaller than 1 cm.According to the ROC curve analysis,the area under the curve of traditional ultrasound TI-RADS classifications,CEUS score and revised CEUS TI-RADS classifications were 0.64,0.75,0.81 respectively,cut-off value was TI-RADS 4a,1 score,TI-RADS 4a respectively,the sensitivity and specificity of evaluating benign and malignant nodules was 45.3％ and 80.0％,69.3％ and 65.0％,82.7％ and 60.0％,respectively.The area under the ROC curve were statistical difference between CEUS score,revised CEUS TI-RADS classifications and conventional ultrasound TI-RADS classifications (both P＜0.05),while CEUS score and revised CEUS TI-RADS classifications without statistical difference.Conclusion CEUS had the revised and improved identification value for thyroid TI-RADS 3,4 nodules.