X-ray photoelectron, emission, and Auger electron spectra of diamond, graphite, and fullerene have been analyzed by deMon density-functional theory (DFT) calculations using the model molecules adamantane derivative (C10H12(CH3)(4)), pyrene (C16H10), and C-60, respectively. The theoretical valence photoelectron, C Kalpha X-ray emission, and Auger electron spectra for the allotropes are in good accordance with the experimental ones. The combination analysis of the valence X-ray photoelectron and C Kalpha X emission spectra enables us to divide the valence electronic distribution in the individual contributions for psigma- and ppi-bonding MOs of the carbon allotropes, respectively. The experimental Auger electron spectra of the allotropes can be classified in each range of 1s-2p2p, 1s-2s2p, and 1s-2s2s transitions for C KVV spectra, and in individual contributions of the chemically different carbon atoms from the theoretical analysis.