The carbon K-shell (1s) X-ray photoelectron spectroscopy (XPS) and near-edge X-ray absorption fine structure (NEXAFS) spectroscopy of the seven isolated-pentagon-rule (IPR) isomers of fullerene C80 have been calculated by means of density functional theory (DFT) theoretically. We have demonstrated the relationship between molecular structures and related X-ray spectroscopies. The dependence of the XPS spectra on the structures of the seven C80 molecules is imperfect, while the NEXAFS spectra show strong dependence on the seven fullerene molecules, so the NEXAFS spectra can be employed to identify all of the studied isomers. The spectral components of different local environments have been explored in detail.