Objective ：To investigate the value of semi-quantitative analysis based on endobronchial ultrasound elastography for hilar and mediastinal lymph node metastasis in patients with lung cancer. Methods :A total of 87 patients with suspected lung cancer who were admitted to our hospital from March 2019 to October 2022 were selected as the research objects, and a total of 147 lymph nodes were examined by elastography and endobronchial ultrasound-guided transbronchial needle aspiration. Conventional ultrasound parameters such as shape, size, echo type, internal echo distribution, and edge clarity of lymph nodes were observed, and elastic imaging parameters such as ultrasound elasticity score and strain rate ratio were observed. The diagnostic value was compared.Results : The diameter of 147 target lymph nodes ranged from 7.9-33.2mm, with an average diameter of 17.23±4.64 mm. Among them, 56 were benign, 34 were lymphadenitis, 13 were tuberculosis of lymph nodes, 9 were sarcoidosis, 91 were malignant, 21 were non-small cell poorly differentiated carcinoma, 19 were small cell carcinoma, 23 were adenocarcinoma and 28 were squamous cell carcinoma. According to MD grouping staging system, 16 for two groups, 20 for the four groups, 28 group of 7, 14 for 10 group, 13 for 11 group. Lymph node diameter, hypoechoic, heterogeneous echo and unclear margin were statistically significant in the differentiation of benign and malignant lymph nodes. The average elastography score of benign lymph nodes was (1.85±0.97) points, and the average elastography score of malignant lymph nodes was (3.36±0.91) points. The test showed that the elastography score of malignant lymph nodes was significantly different from that of benign lymph nodes (P < 0.001). The average strain ratio of benign lymph nodes was (20.62±17.12), and the average strain ratio of malignant lymph nodes was (87.67±49.17). The strain ratio of malignant lymph nodes was significantly higher than that of benign lymph nodes, and the difference was statistically significant (P < 0.001). The AUC of elastography score was 0.854, and the cut-off value of elastography score of benign and malignant lymph nodes was determined to be 2.5 at the maximum value of Youden index (0.626). The AUC of the strain rate ratio was 0.931, and the 95% confidence interval was 0.877-0.985. The cut-off value of the strain rate ratio of benign and malignant lymph nodes was 32.07 when the maximum value of the Youden index was 0.687. ROC curve showed that the area under the curve of strain rate ratio was 0.931, which was significantly higher than that of two-dimensional ultrasound parameters and elasticity score (AUC=0.734, 0.664,0.703,0.559 and 0.854).Conclusion :Endobronchial ultrasound elastography is an easy, simple and non-invasive examination method, which can effectively distinguish benign and malignant hilar and mediastinal lymph nodes, and has a higher accuracy than conventional ultrasound indicators.