Abstract: ［Abstract］Objective To investigate the value of detecting the paratracheal lymph nodes by ultrasound in diagnosis of autoimmune thyroiditis （AIT）. Methods　We selected 101 AIT cases as experimental group. At the same period，35 cases of Graves'disease（GD），31 cases of subacute thyroiditis（SAT），and 60 normal cases were selected as control groups. Lab tests，such as TSH，TGAb，and TPOAb were carried out and the morphology of thyroid，characteristics of two dimensional ultrasound， and colorful Doppler flow were observed. Meanwhile， whether displayed the paratracheal lymph node or not，the aspect ratio of the displayed paratracheal lymph node， corticomedullary differentiation，and the characteristics of colorful blood flow were observed. Results　There were significant difference in lab test indicators （TSH， TPOAB，TGAB） among AIT group，GD group，and SAT group（P＜0.05）. There were significant differences in displayed rate of paratracheal lymph node， number of paratracheal lymph node， aspect ratio of the displayed paratracheal lymph node and colorful Doppler flow among AIT group， GD group， SAT group， and normal group（P＜0.05）， but the indicator of corticomedullary differentiation had no significant difference（P＞0.05）. Conclusion　Ultrasound examination of the paratracheal lymph node has the diagnostic value in diagnosis of autoimmune thyroiditis，and may assist us to judge the nature of diffused thyroid diseases.