Abstract: The Bayanhua group of the Lower Cretaceous in the Hurenbuqi sag of Erlian basin develops a set of deposit of inland river- lake facies clastic rocks. Semi-deep and deep lacustrine source rocks commonly occur in the Tengge'er formation in eastern deep trough of the sag, dominated by lithology of dark gray and gray-black mudstone and shale, with the organic carbon content of greater than 5.0%, the chloroform bitumen "A" of greater than 0.5%, the total hydrocarbon of greater than 1 500 ppm, the type of organic matter is dominated by humosapropelic type (Ⅱ 1 ), and the vitrinite reflectance averaging 0.57%, indicating the thermal evolution is in low-mature oil-generating stage. The potential oil-generation rate is more than 60 mg/g. The total oil-generating quantity is 38.510 9×10⁸ t. The total resource is 1.852 4×10⁸ t in this sag calculated by means of chloroform bitumen "A" method, indicating it is of a certain of petroleum resource and explorative potentials. Among them, the 1st member of Tengge'er formation assumes the largest volume of resources of 1.573 9×10⁸ t, being the main target for exploration. Regionally, some sub-sags in the south and north have the largest resources accounting for a total resource of 89%, being important areas for exploration.

Key words: Erlian basin, Hurenbuqi sag, source rock, characteristic, resource potential, evaluation