Objective To summarize the differences in CT findings of benign and malignant sub-centimeter（（1cm）pulmonary solid nodules with the aim of improving their diagnosis and differential diagnosis. Methods From January 2012 to June 2020，the clinical and CT data of 174 patients with sub-centimeter pulmonary solid nodules（104 benign lesions and 70 malignant tumors）con⁃firmed by postoperative pathological examination were retrospectively analyzed. The CT manifestations of nodules，including distribu⁃tion，morphology，density，nodule-lung interface and the changes of adjacent structures，were analyzed. Univariate and logistic regres⁃sion analysis as well as comparison of different CT features were used to reveal the most valuable signs for differentiating benign and ma⁃lignant.nodules. Results There were significant differences in age，density，nodule-lung interface and lobular sign between the be⁃nign and malignant lesions（P<0.05）. Multivariate logistic regression analysis showed that older patient（OR：1.065；95% CI：1.025～1.107；P<0.001），nodule with mixed density（OR：9.388；95% CI：3.015～29.237；P<0.001），coarse nodule-lung interface（OR：9.060；95% CI：1.504～54.556；P=0.016 ）and lobulation（OR：7.125；95% CI：2.741～18.522；P<0.001）were important indicators of malignancies. In addition，there were significant differences in the specific manifestations of mixed density，spiculation，lobulation and peri-nodular ground-glass opacity between these two groups. A few nodules with calcification，satellite lesions or broad base con⁃nected to the pleura were benign. However，those nodules that caused locally shrinkage of the interlobular fissure with or without pleu⁃ral thickening were malignant. Conclusion For sub-centimeter solid pulmonary nodules shown on CT，if the patients were older，the density of nodules were uneven，the nodule-lung interface were rough，or accompanied by lobulation sign，it is more likely to be ma⁃lignant tumor. Attention should be paid and further examinations and differentiation should be done to determine the nature of the tumor.