Fixed-bed tars of Euphorbia rigida and sunflower pressed bagasse have been investigated for their structures. These mrs were fractionated into pentane-soluble and -insoluble compounds (asphaltenes). Pentane soluble were then solvent fractionated into pentane, toluene, ether and methanol subfractions by fractionated column chromatography. The aliphatic and low-molecular-weight aromatic subfractions of the bio-oils were then analyzed by capillary column gas-liquid chromatography and GC/MS. Further structural analysis of bio-oils and aromatic and polar subfractions were conducted to FTIR and H-1-NMR spectra.