In the 19th century, mediastinal surgery was performed in Western European countries to treat mediastinal diseases. It was not until the mid-20th century that there was a major development. With the increasing incidence of intrathoracic tumors and infectious diseases, both invasive and noninvasive approaches to mediastinal examination have changed considerably. Harken and colleagues first reported transjugular mediastinal exploration in 1954, describing their experience with Jackson’s laryngoscopic supraclavicular incision to explore the mediastinum to determine the presence or absence of mediastinal lymph node metastases in lung cancer, and also introduced the concept that lung tumors with mediastinal lymph node metastases are inoperable. The concept of inoperability of lung tumors with mediastinal lymph node metastasis was introduced. Today, 40 years later, this technique is still considered to have reasonable clinical utility and is important for clinical diagnosis and treatment, and the exploration of the chest lymph nodes by mediastinoscopy has led to the prototype of the chest lymph node drainage map. Mediastinoscopy is now widely used in clinical practice, mainly for lung cancer cases, to identify the presence or absence of metastasis in mediastinal lymph nodes, to diagnose and stage lung cancer, and to formulate treatment plans, providing important reference information. This method is widely used in Europe and the United States, but in China, it is still rarely used and only a few reports have been published. In 1964, Fu Yaoji and others were the first to perform mediastinoscopic surgery in China and achieved good results; in the late 1960s, Qiu Demao and others from Shanghai Pulmonary Hospital applied pediatric tracheoscopy and esophagoscopy as mediastinoscopy; in 1978, Xie Daye and others from Cancer Hospital of Shanghai Medical University used a homemade mediastinoscope to perform 20 cases of mediastinoscopy. In 1998, Wu Yilong et al. reported the use of mediastinoscopy for the differential diagnosis of difficult mediastinal diseases, and in 2001, Wang Jun et al. took the lead in performing TV mediastinoscopy in China. There are not many medical units in China that use mediastinoscopy, mainly for diagnosis rather than treatment, and there are even fewer relevant papers reported in the literature, and many doctors and patients are unwilling to perform diagnostic mediastinoscopic surgery for examination, but are willing to open the chest directly for surgical exploration. It is believed that with the development of medical science and technology and the growing popularity of evidence-based medicine, this technology will be popularized and developed in China under the influence of the work of pioneers and demonstrations. From the practical point of view, mediastinoscopy has a role in lung cancer staging, especially in the diagnosis and differential diagnosis of difficult cases in the chest that cannot be replaced by other methods, and it is an examination method worth advocating. Indications, (1) mediastinal lymph node biopsy, mainly used for the diagnosis and staging of primary lung cancer, metastatic cancer, esophageal cancer, head and neck cancer, lymphoma, inflammatory and sarcoidosis, nodular disease, tuberculosis, pneumoconiosis, etc. (2) Diagnosis of mediastinal tumors, cysts, and displaced organs, such as thymus and thymoma, bronchogenic cysts, teratoma, dermatomatous cysts, embryonic cell or other tumors, displaced neck organs, parathyroid glands, mediastinal goiter, etc. (3) thymectomy for severe myasthenia gravis; (4) mediastinal exploration for parathyroid adenoma; (5) removal of mediastinal cysts; (6) drainage or removal of mediastinal accumulation (hematoma, celiac disease, abscess), etc. In particular, the condition of mediastinal lymph nodes opposite to the cancer focus determines the stage of lung cancer and the indications for surgery, the scope of radiotherapy and the prognosis of the disease. This is the most important indication for mediastinoscopy. Chest X-ray, CT scan, MRI, PET-CT, etc., which are often used at present, can only provide imaging diagnosis of the lesion site, and obtaining cytological samples such as E-BUS is far from replacing the value of large pathological samples obtained by mediastinoscopy for definite diagnosis. Absolute contraindications to mediastinoscopy are rare and include severe cervical arthritis, “cervical spine ankylosis with no posterior elevation,” pediatric patients or those of very short stature, “cervical mediastinal tunnels in which mediastinoscopy cannot be placed, and tracheostomy patients. For small isolated lesions of less than 3 cm in diameter around the trachea, resection of the lesion can be done at the same time as mediastinoscopy. Thymectomy for severe myasthenia gravis, exploration for parathyroid adenoma, removal of mediastinal cysts, drainage or removal of mediastinal accumulation (hematoma, celiac disease, abscess).