The invention discloses characteristic spectrums of lung cancer and pulmonary nodule proteis as well as construction methods and application of the characteristic spectrums. The methods comprise the following steps of extracting total protein from the plasma of a lung cancer/pulmonary nodule patient group and a healthy control group respectively, carrying out enzymolysis by trypsase, carrying out iTRAQ (isobaric Tags for Relative and Absolute Quantification) labeling, carrying out two-dimensional liquid chromatographic and tandem mass spectrometric detection, and carrying out relative quantitative analysis, so that the characteristic spectrums of the proteins related to the lung cancer/pulmonary nodule are obtained, wherein in the characteristic spectrum of the protein related to the lung cancer, the protein with expression differences in the lung cancer patient group and the healthy control group is up-regulated protein (SAA1 (Serum Amyloid A 1), SERPINA1 (Alpha-1-Antitrypsin), CRP (C-Reactive Protein), IGHG4 (Human Immunoglobulin G 4) and a CFH (Complement Factor H)); in the in the characteristic spectrum of the protein related to the pulmonary nodule, the protein with expression differences in the pulmonary nodule patient group and the healthy control group is up-regulated protein (the SERPINA1 and the CRP) and down-regulated protein (the SAA1, the IGHG4 and the CFH). The characteristic spectrums are used for facilitating the research of the biological natures of the lung cancer and the pulmonary nodule, and have important significance for the normative typing of the lung cancer and the pulmonary nodule.