Keywords: 
• coal rock /
• exinite /
• thermal pyrolysis /
• terpanes

Abstract: According to the GC-MS analysis of soluble organic matters extracted from coal and exinite heated in closed system pyrolysis, one characteristic feature of all samples is the relative low abundance of tricyclic diterpanes in saturated hydrocarbon fractions with the detection in the C₁₉ to C₂₆ range. The tricyclic diterpanes and its homologues are derived from the cleavage and release of their precursors in coal framework. The positive linear correllation between 22S/22(S+R) ratios of C₃₁C₃₂αβ hopanes and pyrolysis temperatures indicates that they would be used as the thermal mature parameters. The detection of αββ hopanes in saturated hydrocarbons infers the low maturity of coal samples and the energy for conversion of 17β (H),21β(H)-homohopanes to 17β(H),21α(H). During the thermal evolution of coal rock from low to high maturity, the thermal stability of hopanes is as follows: ββ＜βα＜αβ. The time of hydrocarbon generation from exinite is later than coal according to the geochemical parameter of hopanes, such as occurrence of 17β(H) trisnorhopane and C₂₉βα-hopanes as peak carbon, C₃₁αβ22S/22(S+R) index.