Abstract: Based on the geological study of hydrocarbon migration and accumulation in reservoir of Guantao Fm.of Feiyantan area in Shengli Oil Field, influence of main fault' injection amount and subfault to petroleum migration and accumulation in the formation is discussed by means of a 2-D model in the case of opening faults.Results show that the injection amount of main fault has influence on the effect of subfault to the accumulation of Upper Guantao Fm.There are three kinds: ①while the injection amount of main fault is much enough, the injection amount of layers adjacent to the subfault is most, and is most favorable to the accumulation of oil in layers which connected with subfault; ②while the injection amount of main fault is average, layers besides subfaults have the accumulation of oil only if they connect with main fault; ③while the injection amount of main fault is less, layers adjacent subfault have little oil, it is not favorable for the accumulation of oil.It is important to explain the oil pool forming concerned with subfaults in Guantao Fm., Feiyant an area.