Abstract: The compositions and contents of the gas products produced by pyrolysis reactions of four components separated from the Tarim crude oil and that of liquid products from saturates of Tarim crude oil under 30 MPa and different temperatures were analyzed by GC and GC/MS respectively. The results showed that contents of C₁ component in gas products obtained from pyrolysis of the four components were significantly higher than that of C₂ to C₅ components, and the total gas yields as well as the gas yields of the C₁~C₂ components increased with the increase of the pyrolysis temperatures. The total gas yield of the four components was in the order:asphaltene > saturates > aromatics > resin, as the temperature above 450℃ was adopted. The pyrolysis reaction degree of the main component C₁₂~C₁₈ in saturates increased with the increase of temperature. At 410℃, the pyrolysis of saturates was mainly cracking reaction, and the degrees of cracking and condensation reactions increased at above 490℃, which led to the increase of gas yields as well as the main component of the liquid products to the large molecular hydrocarbon. Discrete degree of component distribution in liquid products augmented with the increase of pyrolysis temperature.