Abstract: The characters of chemical composition and structures of the asphaltene and resin of chloroform rock extracts and crude oils are discussed.Using high performance liquid chromatography,asphaltene and resin are respectively separated into three components,i.e.neutral,weak polar and polar.Furthermore,element composition,infra-red spectrum and hydrogen nuclear magnetic resonance are analysed for these three components.Experiments show that the aromaticity of the asphaltene components evidently increases with the the polarity,while differences in hetero-atom-substitution and aromaticity exist among the three resin components.These features are all related to the types of the precursor and maturity of source rocks.