With the promotion of CT physical examinations, lung nodules are being found in an increasing percentage of the population, as high as 10-20%. For this population, the majority of lung nodules (over 96%) are benign. However, there is also a proportion of ground glass nodules (GGO or GGN) that are a sign of early stage lung cancer. How to differentially diagnose and avoid missing the diagnosis, while avoiding overtreatment of benign nodules is an important issue. The benignity or malignancy of nodules is judged based on a combination of manifestations such as size, morphology, and past medical history. Most small nodules require more than 3 years of follow-up before definitive results can be obtained. This requires precise monitoring of the nodules. Close monitoring of the volume and density of the nodules will provide an important basis for determining the treatment of the nodules and whether to treat them surgically. From time to time, some diagnostic points for pulmonary nodules will be provided.