Structural features of > 300 degrees C fractions of six Chinese shale oils, namely the Huadian, Wangqing, Fushun, Longkou, Maoming and Yaojie oil, have been characterized using H-1 nuclear magnetic resonance, C-13 nuclear magnetic resonance and Fourier transform infrared techniques. Based upon the results obtained from H-1 nuclear magnetic resonance and C-13 nuclear magnetic resonance, the distribution of various types of hydrogen and carbon atoms, and related structural parameters in > 300 degrees C fractions were determined. Different types of functional groups were studied based on the curve-fitting analysis of Fourier transform infrared spectra with Gaussian function. The results showed that the > 300 degrees C fraction of Huadian shale oil had the highest ratio of aliphatic carbon among the six samples. Meanwhile, the average carbon number of substituents in Huadian oil's > 300 degrees C fraction was the highest, and had the value of 8.98. Moreover, the Huadian sample owned the lowest degree of branching of aliphatic chain, whereas it had the highest ratios of -CH2- and -CH3-. These results indicated that, in Huadian oil's > 300 degrees C fraction, the alkyl carbon chains were longer, whereas the branched chains were less (in number) compared to other samples. Furthermore, the curve-fitting analysis indicated that 2 and 3 adjacent H deformations were dominant in aromatic structures. The oxygen-containing groups in > 300 degrees C fraction of Chinese shale oil were mainly the C-O groups, followed by the C-OH groups, O-C=O groups and conjugated C=O groups. In summary, > 300 degrees C fractions of Chinese shale oils showed similar differences with regards to the elemental compositions and functional groups.