Laboratory in situ combustion experiments were performed to determine the basic parameters prior to field projects, using a self-made combustion tube and S1-38-330 crude oil from Liaohe Oilfield. These basic parameters, the oil's ignition temperature range from 340 to 360 degrees C, the apparent atomic H/C ratio of 1.044, the oxygen utilization of 52.15%, the oil recovery factor of 78.6%, the combustion front movement velocity of 0.20 cm/min, the maximum fuel consumption of 28.99 kg/m(3), and the maximum air requirement of 298.6 N m(3)/m(3), etc., were determined in the experiments. The gas chromatograms showed that the crude oil had undergone a series of pyrolysis reactions during combustion, and it could also be proved via the results of aromatics mass spectrometry that anthracene was generated during this process.