Pulmonary nodules are identified by high-resolution CT of the chest as ground glass nodules, solid nodules or partially solid nodules. If pulmonary nodules show solid changes they are mostly benign, unless the nodules are larger than 3 cm, they need to be alerted to the occurrence of malignant tumors, which are mostly seen in solid lesions left by incomplete absorption of the lung after a previous infection with tuberculosis or inflammation. Solid pulmonary nodules also include inflammatory pseudotumors and tuberculosis globules, but in both cases the nodules are smaller than 3 cm and have smoother borders. Solid pulmonary nodules larger than 3 cm with short burrs, lobar signs, pleural pulling signs, pleural depression signs and clinical appearance of cough, blood in sputum, progressive weight loss with chest pain, etc., and biochemical examination also suggesting malignant tumor changes, should be highly suspected of solid nodules as early stage lung cancer, which can be treated by surgical resection at the earliest possible time by thoracic surgery.