Abstract: The composition and crystal structure parameters of different asphaltene were studied in this paper. The results show that the content of carbon and hydrogen occupies more than 85%, the content of sulfur is higher in petroleum asphaltene and the content of oxygen is higher in coal tar asphaltene. The XRD results show that the aromatic layers of petroleum asphaltene can pile up to amorphous association by π?π interaction. The distance between adjacent aromatic layers is less than that of adjacentalkyl chains of petroleum asphaltene because of the influence of hydrogen-bonding interactions and steric hindrance. There is not (002) peak in XRD spectrum of coal tar asphaltene because the size of aromatic layers and the interaction are both small, so the aromatic rings can’t form effectivestacking structure.

Key words: asphaltene, element composition, crystal structure parameter, XRD