Abstract: In order to study the role of faults in hydrocarbon accumulation in Pubei Oilfield, northern Songliao Basin, based on the characteristics of formation deformation caused by faults, the oil-source faults in the Putaohua oil layer in Pubei Oilfield were reclassified and their control on hydrocarbon accumulation in the layer were investigated by fine analysis of fault seismic characteristics.According to whether the fault connects the source rock and the target reservoir, and whether the fault is active during the hydrocarbon accumulation period (including the fault activity with relatively large fault throw and the weak activity without obvious fault throw), three types of oil-source faults are divided.Type 1 is the penetrating oil-source fault that connects the source rock of the first member of Qingshankou Formation (K₂qn₁) and the Putaohua oil layer and breaks through the T₀₆ reflector (the bottom interface of the third member of Nenjiang Formation).Type 2 is the oil-source fault with fold deformation at the end and connecting the source rock of K₂qn₁ and the Putaohua oil layer, which has no obvious activity during the hydrocarbon accumulation period but causes fold deformation at the end of the fault.Type 3 is the oil-source fault with differential walls, which connects the source rock of K₂qn₁ and the Putaohua oil layer, without obvious activity during the hydrocarbon accumulation period but with the deformation difference between the two walls.The research shows that the oil-source fault is more consistent with the plane distribution of oil and gas in the Putaohua oil layer.Especially, the penetrating oil-source fault has the most significant control on hydrocarbon accumulation.This reveals the influences of the activity intensity of oil-source faults and the number of hydrocarbon accumulations controlled by the configuration of oil-source fault and fault trap on the differential hydrocarbon accumulation.The research findings can be referential for analyzing the control of oil-source fault on hydrocarbon accumulation in similar blocks.