Preoperative mediastinal lymph node staging for non-small cell lung cancer (NSCLC) can be divided into non-invasive imaging techniques staging and invasive surgery techniques staging . Noninvasive imaging techniques are not sufficiently reliable in many situations. Computed tomography (CT) has been used as a routine inspection due to the anatomical images it provides. Magnetic resonance imaging (MRI) and diffusion weighted imaging (DWI) have not been widely applied. As the most accurate technique of noninvasive staging, positron emission tomographycomputed tomography (PET-CT) still has a higher rate of false negative. Invasive staging technique is safe and effective in mediastinal lymph node staging. Mediastinoscopy is the gold standard for invasive mediastinal staging till today. Endoscopic ultrasound-needle aspiration techniques and video-assisted thoracoscopic surgery (VATS) are also safe and effective. Invasive staging technique is the first choice of the re-staging in patients after induction therapy.