Abstract: Objective: Analyzing the performance of focal ground glass that under MDCT thin thickness reconstruction, and obtaining CT features of focal ground glass opacity from early stage lung cancer. Method: 53 clinically or pathologically confirmed f GGO were collected and analyzed clinical informations and imaging features including lesion location and size, shape, margin, interface, internal density, pleural indentation, vacuole, air bronchus-charging sign and blood vessel clustering. Statistical analyze the differences between the benign and malignant. Results: There were statistical differences between benign and malignant fGGOs in terms of margin(P = 0.001), interface(P = 0.000) and blood vessel clustering(P = 0.009) as well as gender(P = 0.120), age(P = 0.437), location(P = 0.565) size(benign 1.55 ±0.67) cm, malignant(1.54 ±0.85) cm,(P = 0.978), shape, vacuole(P = 0.100), air bronchus-charging sign(P = 0.211) and pleural indentation(P = 0.243) doesn't significantly found in malignant fGGOs. Conclusion: Margin, interface and blood vessel clustering can make contribute to early lung cancer diagnosis and differentiation of benign and malignant fGGOs.