A 3mm ground glass density nodular shadow is more serious if malignancy is considered, and less serious if it is benign. For grinding glass nodular shadow, clinicians are more cautious, because many malignant lung nodules have grinding glass-like changes, but grinding glass nodules are not always malignant tumors, there are still benign lesions possible. Some patients with pneumonia, tuberculosis, or interstitial lung disease, etc., the lung imaging may have ground-glass changes, at this time, the ground-glass shadow nodules are generally benign, and after strict anti-infection and other treatments, the nodules may be reduced, or even disappeared. If the 3mm grinding glass density nodule shadow is specifically manifested as burr-like, lobulated, vascular sign, pleural pulling sign, clinical symptoms manifested as blood in sputum, chest tightness and breathlessness, fatigue, emaciation, etc., or after regular review, found that the nodule in the short term there is a significant increase in the likelihood of malignant nodules, need to be treated as soon as possible surgical. The presence of a 3mm ground glass density nodule shadow suggests further consultation in the thoracic surgery department.