High-resolution PMR and ESR have been applied to aqueous dispersions of graphite oxide. The PMR spectra show three resonances. The signals in the region ofδ 7 ppm andδ 0 ppm are due to protons in water molecules directly bound to electrondonor centers in the graphite oxide respectively of carbonyl and free-radical types. The latter case is characterized by a single isotropic signal in the ESR spectrum having g factor 2.003. The third broad PMR signal (δ 5 ppm) relates to water molelcules placed between the layers of the graphite oxide in hydrogen-bonded associated forms.