Abstract: Purpose: To analyze CT manifestations of fGGO for improving diagnosis of early lung cancer. Methods: Retrospective analyze lung cancer cases presenting as fGGO confirmed by operation and pathology with complete clinical CT data, observe its size, shape, margin, density and other lung cancer signs, as well as imaging diversity during follow-up CT scan. Result: 34 cases included 7 pGGO and 27 mGGO, showed well-defined interface, lobulated border and spiculated margin vacuole sign and air bronchogram, surrounding with pleural indentation sign and blood vessel cluster sign. In follow up, larger size and higher percent of solid component were seen in fGGO, with more solid lesions in pGGO, larger size in mGGO, lobulated border and spiculated margin, pleural indentation sign and blood vessel cluster sign. Conclusion: CT manifestations of lung cancer as ground-glass opacity have certain characteristics, CT follow-up has high value to the identification between benign and malignant fGGO.