Non-solid nodule 0.9 cm in the lower lobe of the left lung, whether it is serious or not needs to determine the nature of the nodule, and the degree of benignity or malignancy of the nodule needs to be assessed. Left lung lower lobe non-solid nodule 0.9 cm need to assess whether the patient has cough, cough sputum and other clinical symptoms, if the non-solid nodule clear boundaries, internal echogenicity regular, no vascular supply, no pleural pulling and other signs of malignant changes, to consider the possible existence of inflammatory changes, misshapen tumors, pulmonary tuberculosis, and other benign lesions. If there are inflammatory changes, it is recommended to take oral or infusion antibiotics for about two weeks under the guidance of a doctor, and choose antibiotics such as cefadroxil cefuroxime sodium or levofloxacin for treatment, and then pay attention to observing whether the nodule decreases in size in one month, and if it disappears, it is considered to be related to inflammation and infection. If there is malignant disease, fine-needle aspiration biopsy is needed, and if the diagnosis is clear, surgical treatment is needed. For the non-solid changes of lung nodules 0.9 cm persistently does not disappear, it is recommended to pay attention to the follow-up observation, can be 3 months, 6 months, 9 months, 12 months for follow-up, to observe the growth of nodules. It is recommended to consult the respiratory medicine department of regular hospitals to avoid delay.