Tahe asphaltene (T_A) was separated into heavy component(T_A1) and light component (T_A2). The surface morphology, crystal structure and functional group structure of T_A, T_A1 and T_A2 were characterized by Scanning Electron Microscope (SEM), X?ray diffraction (XRD), Fourier Transform Infrared Spectroscopy (FT?IR) and ¹H?Nuclear Magnetic Resonance Spectrum (¹H?NMR). The results show that TA has less long?chain structure, more branched chains in side chains, and is mainly composed of short branched alkyl structure such as methyl, ethyl and propyl. Sub?components T_A1 and T_A2 show obviously different microstructure after separated from T_A. TA1 has the highest degree of graphitization, the longest branched chain, more side?chains of aromatic ring, less branched chains of alkyl side?chains and relatively strong aromaticity, while T_A2 has lower degree of graphitization, more branched chains of alkyl side?chains, less side?chains of aromatic ring and relatively weak aromaticity.