GroundCglass opacity (GGO) of the lungs is most often found during a physical examination when a chest radiograph or low-dose CT scan of the chest is taken. Patients usually do not have uncomfortable symptoms such as cough and fever. What will we do after GGO is found? 1. A thin-layer CT with 3D reconstruction of the chest should be performed, which can provide detailed observation and precise localization of the lesion. It helps to identify benign and malignant GGO, and GGO with obvious lobulation, vacuolation, pleural depression sign or obvious solid component suggests malignant lesion. This test allows regular dynamic observation of lesion development, and inflammatory reaction may be considered if the lesion dissipates or shrinks significantly during follow-up; if the GGO increases, the lesion density becomes solid, or if there are also tumor microvascular CT signs, it suggests a malignant lesion. 2.PET-CT examination is an important examination in lung cancer diagnosis and treatment, which can judge the benignity and malignancy by tumor metabolism of drugs, and also can detect whether there is metastasis to other organs. However, it has limited diagnostic value for GGO, especially pGGO, and is not routinely recommended. 3. GGO intrapulmonary and other organ metastases rarely occur, and its imaging manifestations are mostly characterized by small and thin shapes, so it is also very difficult to make a clear pathological diagnosis through bronchoscopy and percutaneous lung puncture biopsy, and is not routinely recommended. 4. GGO is not a unique imaging manifestation of lung cancer, as inflammation and interstitial changes in the lung can also have similar manifestations. Anti-inflammatory treatment for differential diagnosis of GGO is also a routine clinical practice. Our experience is that after two weeks of anti-inflammatory treatment, we should rest for two weeks and then review the chest CT to compare the changes of lesions, if the lesion shrinks or disappears, it means it is a benign lesion. Otherwise, it should be taken seriously. 5.Should GGO be observed or operated? This is a difficult question to answer. There are international guidelines, but there are specificities in the actual clinical implementation. Our experience is that once GGO is detected and the patient has a strong desire for surgery and high mental stress, it can be treated surgically. For lesions smaller than 10 mm, whether pGGO or mGGO, observation can be performed. Considering the long tumor multiplication time of GGO lesions, the observation period is at least 3 years, during which the patient is examined once every six months to a year, and if there is any change in the size of GGO, it is promptly treated. For lesions larger than 10mm, surgery is recommended, with preoperative CT puncture localization if necessary, and surgery can be considered thoracoscopic wedge resection or lung segmental resection.