The chemical bonding and electronic structure of carbon nanotubes were investigated with high-resolution C K-edge near-edge X-ray absorption fine structures using total electron yield and fluorescence yield. The measurements probe the densities of state above the Fermi level. The newly observed peaks at 284.5 and 290.5 eV are attributed to the rolling of the carbon layers and defects of the nanotubes, respectively. The high-resolution C K-edge spectra of carbon nanotubes are of fundamental interest to the properties and analysis of carbon nanotube. (C) 2002 Elsevier Science B.V. All rights reserved.