It has been shown that proton nuclear magnetic resonance spectra of fractions obtained by gel permeation Chromatography techniques can yield significant information in the characterization of petroleum residuals. Application of empirical relationships developed for the analysis of NMR spectra is shown to be useful when applied to gel permeation Chromatography fractions. Whole residues and a deasphaltened fraction have been separated and studied. Unit weights and aromaticities have been obtained by NMR and compared with molecular weights from vapor pressure osmometry measurements. In addition, supplemental information from infrared and mass spectrometry on GPC fractions has been used to characterize a “neutral” portion of the residue.