Abstract: Objective: To investigate the clinical value of bronchial ultrasound elastography in the differential diagnosis of hilar and me-diastinal lymph nodes. Methods: Between March 2015 and June 2017, 68 patients in the Second Hospital of Lanzhou University were enrolled. Endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) was performed in 68 patients whose thoracic computed tomography scans showed hilar or mediastinal lymph node enlargement, and a total of 121 enlarged lymph nodes were punctured. The target lymph nodes were examined by conventional trachea and elastography, and the parameters of routine ultrasound and elastography were recorded. The pathological results of EBUS-TBNA puncture were used as the gold standard for diagnosis, and the diagnostic sensitivity and specificity of various parameters of conventional ultrasound and elastography were calculated. Logistic regression analysis was used to evaluate the clinical value of differential diagnosis of benign and malignant lymph nodes. Results: The best diagnostic value of the proportion of blue area in the diagnosis of benign and malignant hilar and mediastinal lymph nodes was 0.6, diagnostic accuracy was 87.10%, sensitivity was 89.2%, specificity was 79.33%, positive predictive value was 89.23%, negative predictive value was 72.31%, area under the curve was 0.902, and diagnostic value was significantly higher than that of conventional ultrasound parameters and the elasticity score. The Logistic regression analysis showed that the main factors affecting the diagnosis of benign and malignant hilar and mediastinal enlarged lymph nodes were short diameter, boundary, uniform echo, blood supply, and the ratio of elastography blue area. Conclusions: The proportion of blue area on ultrasound elastography has a high clinical value in the differential diagnosis of benign and malignant hilar and mediastinal lymph nodes and in the precise guidance of EBUS-TBNA operation.