Abstract: A method for the analysis of saturated hydrocarbons in crude oil was established by comprehensive two-dimensional gas chromatography coupled to time-of-flight mass spectrometer(GC×GC/TOFMS). All compounds were identified according to their family characteristics and each spectrum. Alkanes， cyclic alkanes， bicyclic alkanes， adamantanes， diamantanes， terpanes， steranes and hopanes are separated into easily recognizable bands in the GC×GC chromatogram. The characteristics of terpanes， hopanes and adamantanes’ contour chromatogram are defined. C₃₁—C₃₅ tricyclic terpanes were often neglected in the past. Provide petroleum geological experiment workers reference to carry out their work on GC×GC/TOFMS. Compare with the GC/MS, GC×GC/TOFMS has higher sensitivity and bigger peak capacity, which is more suitable for the analysis of complex mixture systems. It will be a helpful tool in the petroleum geological experiment.