Abstract: Objective: To research CT imaging spectroscopy quantitative analysis of value in the differential diagnosis of peripheral lung cancer and pneumonia in the mass. Methods: Retrospective analysis in July 2011 to February 2015 to our hospital for treatment of patients with solitary pulmonary mass total 84 cases as of this study will be divided into around 38 cases of lung cancer patients and 46 patients with pneumonia mass cases of patients with CT imaging spectroscopy quantitative analysis, observed in patients with test results, analyze its diagnostic value. Results: vein CT values of peripheral lung cancer patients in different ke V pneumonia were significantly higher than mass group, the two groups have significant difference(P<0.05), peripheral artery CT values in patients with lung cancer were significantly different ke V higher than pneumonia mass group, the two groups have significant difference(P<0.05), iodine concentration and the slope of the energy spectrum of patients with peripheral lung cancer and pneumonia in arteriovenous mass of patients had significant differences(P<0.05), and water There was no significant difference(P>0.05) concentrations. Conclusions: CT imaging spectroscopy for quantitative analysis of high peripheral lung cancer and pneumonia mass differential diagnosis accuracy, a good clinical value.