Tamtsag Basin is an important overseas hydrocarbon production base of Daqing Oilfield. Based on the dynamic properties and the tectonic evolution characteristics of the tectonic movement in the basin,the basin is divided into three structural strata from the bottom to the top,including fault-depression,fault-depression transformation,and depression.During the fault-depression,the passive rifting titled and uplifted the strata,to form a large number of antithetic faults which were opposite to the stratigraphic tendency. At the end of the deposition of Yimin Formation,the basin was strongly reversed under the action of regional compressive and torsional stress field,and many faults were formed with extension,compression,and torsion step by step. By analyzing the types and distribution of drilled hydrocarbon reservoir in the basin, it is believed that antithetic faults and reverse faults control the hydrocarbon accumulation.According to the configuration relationship of source-reservoir-caprock association,the basin is divided vertically into upper,middle,and lower three sets of hydrocarbon systems. The distribution of hydrocarbon in different systems is complementary,the lower hydrocarbon system dominated by the first member of Nantun Group is the most important producing layer,and the reservoir type is mainly blocked by reverse fault. In the plane,hydrocarbon distributions are controlled by faults. Hydrocarbon is mainly arranged as a“strip”along the antithetic fault in the lower system and gathered near the reverse fault in the upper system. By analyzing the controlling mechanism of antithetic faults and reverse faults,two kinds of hydrocarbon accumulation mode are summarized,including the lower uplift hydrocarbon accumulation backed by antithetic fault and the secondary hydrocarbon accumulation controlled by the reverse fault in research area.