Fleischner Society guidelines for the management of pulmonary ground glass density nodules 1. Isolated, pure GGO less than or equal to 5 mm in diameter do not require follow-up Especially in the elderly, as they represent AAH pathologically and, in a few cases, adenocarcinoma in situ. The scan layer thickness must be 1mm to determine if it is a true GGO. 2. Isolated, pure GGO greater than 5mm in diameter is reviewed after 3 months to see if the lesion disappears. If persistent, review annually for at least 3 years. Pathologically AAH, adenocarcinoma in situ and a small percentage of microinfiltrating adenocarcinoma, antibiotics are not recommended.PET is of little value.CT-guided puncture is not recommended and has a low positive rate. If the lesion increases in size or lesion density, surgical treatment is indicated. thoracoscopic wedge surgery, lung segment surgery, and subsegmental resection are recommended. 3, isolated partially solid density GGO, especially those with solid component greater than 5 mm, should be considered as possible malignant change when the lesion is found to be enlarged or unchanged on review after 3 months. A group of data showed that the possibility of malignancy was 63% for partially solid density nodules and 18% for pure GGO. Most of the large pure GGO are aggressive lesions. They are often inflammatory in women and young patients. CT-guided puncture is not recommended. The procedure recommended is thoracoscopic wedge surgery, surgical resection of lung segments, and lobectomy is not recommended. 4, Multiple GGO with clear margins less than 5 mm should be taken as a more conservative option, and follow-up after 2 and 4 years is recommended. 5.Multiple pure GGO with at least one lesion larger than 5 mm but without particularly prominent lesions are recommended for review after 3 months and long-term follow-up for at least 3 years. 6.Multiple GGO with prominent lesions and major lesions requiring further management. On first review after 3 months, if the lesion persists, more aggressive management of larger lesions is recommended, especially if the solid component within the lesion is greater than 5 mm. The recommended procedure is thoracoscopic wedge surgery, surgical resection of the lung segment, and annual follow-up of the patient after surgery for at least 3 years.