If a lung nodule of 3cm is malignant, it may be early or intermediate, which needs to be confirmed according to the specific situation; if it is benign, there is no difference between early and intermediate. Clinical staging is not only based on the size of the nodule, but also on the presence or absence of lymph node metastasis and distant metastasis to determine the early or intermediate stage of the nodule. The T-stage of a 3cm lung nodule is T2, and it is necessary to further improve the tumor series, sputum test for cancer cells, bronchoscopy, puncture biopsy, enhanced CT and other related examinations to clarify the N and M staging, and consider whether it is early or intermediate. For benign nodules, such as malignant tumors, chondrosarcoma, fibroma, hemangioma, even if the size of the nodule is 3cm, there is no stage, but early surgical resection is recommended for larger diameter nodules. If the nodule is malignant, surgical treatment, radiotherapy, chemotherapy, target cell drug therapy, gene therapy, immunotherapy and so on should be considered according to the condition. When the patient’s chest X-ray or lung CT shows nodules in the lungs, the diameter <5mm is mostly benign nodules, the diameter of 5~8mm when the nature of the uncertainty, the diameter >8mm when the possibility of malignant nodules. Early or intermediate need further examination to determine.