purpose of this study is to analyze the differences between the absorption-spectra of normal and cancerous esophagus tissue so as to determine the possibilities of cancer esophageal specimens and establish an analytic model. In this study, normal and cancerous human esophageal specimens were provided by National Taiwan University Hospital. Absorption-spectra of the normal esophagus tissue are used for definition of standard-spectra. In order to distinguish absorption-spectra between normal and cancerous esophageal tissue, we conclude the characteristics of the standard spectrum and analysis the correlation between each absorption-spectra and standards-spectrum. We can determine the possibility of cancer of unknown samples using our analysis model. In the future, this method may benefit the medical diagnosis of esophageal cancer.