Courtauds type II PAN-based carbon fiber surface was analyzed with both core level and valence band XPS. Compared to Du Pont and Amoco pitch-based carbon fibers with different moduli, the Courtauds type II PAN-based fiber had much more oxidized components on the surface [See Y. Xie and P. M. A. Sherwood, Appl. Spectrosc.43, 1153 (1989); Chem. Mater.1, 427 (1989);2, 293 (1990); Appl. Spectrosc.44, 797 (1990); Chem. Mater.3, 164 (1991); Appl. Spectrosc.44, 1621 (1990);45, 1158 (1991); Y. Xie, T. Wang, O. Franklin, and P. M. A. Sherwood,ibid.46, 645 (1992).] The type II fiber had a much less graphitic structure in both the surface and the bulk than the pitch-based fibers as evidenced by both the XPS and XRD. It also had a notable nitrogen content on its surface but less than the Hercules AU4-12k and AS4-6k PAN-based fibers. However, no nitrogen was found on any of the pitch-based carbon fibers measured in our laboratory. Our previously reported work [Y. Xie and P. M. A. Sherwood, Chem. Mater.1, 427 (1989);2, 293 (1990); Appl. Spectrosc.44, 797 (1990); Chem. Mater.3, 164 (1991); Appl. Spectrosc.44, 1621 (1990);45, 1158 (1991); Y. Xie, T. Wang, O. Franklin, and P. M. A. Sherwood,ibid.46, 645 (1992)], showed that XPS valence band spectra were more sensitive to chemical environment on the carbon fiber surface than core level spectra and could well be interpreted by X–αcalculations with model compounds. In this work, the valence band spectrum showed that there were nitrogen and different types of oxygen species on the type II fiber surface.