In order to evaluate the residual oil and gas resources and identify the favorable exploration areas, the hydrocarbon-controlling function of hydrocarbon source rocks in Damintun Depression is studied in this paper. The origin, the accumulation period, the distribution extent and resource potential of oil and gas in Damintun Depression are found to be controlled by the effective hydrocarbon source rocks. The volumes of hydrocarbon expulsion, the resources and the residual resources are calculated based on the theories of the hydrocarbon accumulation system and the hydrocarbon-controlling function of the geological threshold. The Damintun Depression is divided into two reservoir-forming combinations of the upper and the lower parts, with a total of ten hydrocarbon accumulation systems. The total volumes of hydrocarbon expulsion are 14.66×10⁸t, the volumes of the resources are 6.34×10⁸t and the volumes of the residual resources are 3.098×10⁸t. There are three most favorable exploration areas, including the hydrocarbon accumulation system I_lower, the hydrocarbon accumulation system III_upper and the hydrocarbon accumulation system II_upper. Their volumes of residual resources are, respectively, 1.163×10⁸, 0.567×10⁸ and 0.409×10⁸t.