The dome structures are widely developed in the Ordovician carbonate strata in the Shunbei area of the Tarim Basin. However,the structure characteristics,formation mechanism and petroleum geological significance of the dome structures are still not clear,due to lack of targeted research.Methods: In this paper,based on high- precision 3D seismic data of the Shunbei area,a geometric quantitative analysis of the dome structures was carried out to determine its spatial distribution characteristics and internal structure styles.Then,make use of regional tectonic background and the characteristics of inner basin structure development,the formation mechanism of the dome structures was also clarified.Furthermore,combined with the production dynamic data,the controlling significance of reservoir and hydrocarbon accumulation of the dome structures is discussed.Results: The research shows: ① The dome structures exhibit elliptical to near circular planar shape with NE40°main frequency direction of long axis and NW20°main frequency direction of spreading trend.The distance from the dome structures to the primary strike- slip faults is normally distributed. ② The dome structures develop the thrust faults in the edge and ring faults in the centre.The dome structures uplift amplitude is positively correlated with the planar projection area and gradually weakens downwards from the T74 interface. ③ The dome structures’ formation has no relationship with the primary strike- slip faults under the same stress background.It is controlled by the vertical intrusion activity of magma thermal fluid along the secondary strike-slip faults,which causes uplift deformation of the upper formation.④ In carbonate strata,the boundary thrust faults and top tensile fracture of the dome structures can be good reservoirs.The location of boundary thrust faults is consistent with the distribution of “beads” (representing reservoir in seismic),indicating that is inferred to be the development location of high-quality reservoirs.Conclusions: The spatial distribution characteristics of the dome structures developed in the Ordovician strata is controlled by strike-slip faults.The formation mechanism and development degree of the dome structures depend on magmatic activity.The dome structures with good reservoir and hydrocarbon accumulation conditions have great prospects for petroleum exploration.This study can deepen the formation understanding of deep dome structures in the basin and also provide guidance for the exploration and evaluation of new exploration types in the Shunbei area and even the whole Tarim Basin.