Raman spectroscopy is a vibrational spectroscopic technique that can be used to optically probe the molecular changes associated with diseased organs. The objective of our study was to explore Raman spectroscopy for detecting different stage changes of serum taken from lung cancer patients. Serum samples were obtained from 26 lung cancer patients at different periods before operation. Raman spectra differed significantly at different stages, showing molecular changes with the development of lung cancer. The ratio of Raman intensities excited by 488.0 nm and 514.5 nm laser decreased as lung cancer progress. The results of this exploratory study indicate that Raman spectroscopy provides significant potential for the noninvasive monitoring of lung cancer