Abstract： Pulmonary nodule/mass is a common respiratory disease which includes various benign and malignant lesions.The proportion of benign and malignant nodule/mass varies from study to study,the ratio of benign lesions is higher in solid or mixed solid nodules and the ratio of malignant lesions is higher in ground glass nodules.Chest CT plays an important role in the investigation of pulmonary nodule/mass.The CT findings of nodule/mass size,margin,and internal characteristics can give a little clue to diagnosis.The diagnostic accuracy of fiberoptic bronehoseopy is lower than that of CT-guided percutaneous lungbiopsy for pulmonary nodule.