Abstract Graphite oxide (GO) and several of its derivatives have been studied using 13C and 1H NMR. The 13C NMR lines at 60, 70 and 130 ppm have been re-assigned. The > C C < double bonds are relatively stable in comparison with the COC and COH groups. There are at least two magnetically inequivalent COH sites, and the structure does not necessarily possess long-range order. Water molecules interact very strongly with the structure. The results reveal a number of new structural features of graphite oxide.