Objective: To discuss the value in the differential diagnosis of benign and malignant in ulmonary ground-glass opacities with multislice spiral CT. Methods: Selected 31 patients in Beijing North hospital with spiral CT examination of the chest as the research object, the lungs differential diagnosis of ground-glass image analysis to pathological findings as diagnostic criteria, analysis Imaging features of benign and malignant grinding glass shadow. Results: Malignant lesions with pleural indentation, spiculation, lobulation, such as performance-based, clear boundary between the two groups in the pleural indentation, spiculation, points Ye Zheng, clear boundary comparing with statistical significance(x2=11.138, x2=6.482, x2=4.306, P<0.05). Meanwhile benign lesions showed a round or oval, and malignant lesions with irregular shape and multi-nodular-like performance-based fusion of the two groups in a round or oval, irregular and more fusion-like nodules difference was significant, the statistical significance (x2=11.138, x2=6.482, x2=4.306, P<0.05). Conclusion:Application of multislice spiral CT examination of the chest can be on the ground glass by special signs and morphological comprehensive analysis, benign and malignant, with a high value.