Abstract: Yin'gen-Ejinaqi Basin is a large sedimentary basin with a relatively low degree of oil-gas exploration in China. The exploration practice since the 13th Five-Year Plan(2016-2020) has confirmed that the Cretaceous Baiyingebi Formation is the main source rock series, and three assemblages develops in Carboniferous-Permian, Jurassic, and Cretaceous reservoirs, forming various types of oil-gas pools such as lithological and structural-lithological reservoirs, bedrock buried-hill reservoirs, and unconventional reservoirs. However, the development characteristics of source rocks, main controlling factors of hydrocarbon accumulation, and resource potentials of various sags vary due to the differences of late tectonic movements in Yin'gen-Ejinaqi Basin, thus affecting the overall cost-effective development of the basin. Based on recent exploration practices and understandings, as well as analyses of the basic accumulation conditions, this paper conducted a new round of evaluation on the resource potentials of Yin'gen-Ejinaqi Basin. The results indicate that there is great resource potentials of the Cretaceous lithological and structural reservoirs in Chagan sag, Guaizihu sag, Hari sag, and Tiancao sag, which are the main areas for oil-gas exploration and development. The Carboniferous-Permian buried-hill cave-fractured reservoirs in bed rocks in Lujing sag, Guaizihu sag, and Jigeda sag can provide favorable conditions for high production and hydrocarbon enrichment and are new types of resources for cost-effective exploration. The Cretaceous shale oil and reservoirs in Chagan sag, Guaizihu sag, and Hari sag and the Jurassic lithological reservoirs from the coal-bearing source rocks in Aoxinan sag have certain exploration potential and are new fields for further exploration. In Yin'gen-Ejinaqi Basin, the conventional oil resources amount to 14.39×10⁸t, the conventional gas resources amount to 451.17×10⁸m³, and the unconventional shale oil resources amount to about 5.6×10⁸t, showing excellent exploration prospects.