This study was performed in order to evaluate shale oil in the first member of the Qingshankou formation (K(2)qn(1)) in the Songliao basin in northeastern China. The evaluation was carried out using immature type I kerogen kinetics in a closed system, two wells drilled into oil prone source rocks, in order to apply Rock-Eval, mineral composition and residual hydrocarbon analysis, and the hydrocarbon sorption method. The "oil windows" for K(2)qn(1) in mudstone and shale wells range from 0.6% to 1.05%, with maximum hydrocarbon generation at around 420 mg of hydrocarbon per gram of total organic carbon. In addition, the brittle mineral contents of K(2)qu(1) conform to the requirements for industrial oilfield development and exploitation. Our results demonstrate that there is clear potential for shale oil exploration in the K(2)qn(1); a highly potential zone is defined as low risk at burial depths of greater than 2065 m for well H14, while well X83 exhibits relatively discrete depth based on oil saturation and production indexes as well as free hydrocarbon content. In contrast to oil saturation index, the generation-sorption method is reasonable to assess free oil in organic-lean rocks. Restricted maturity conditions of free oil are represented by Easy%Ro values of 0.8-0.97% based on three sets of parameters-generation, adsorption, and residual oil-for K(2)qn(1) mudstones and shales in the Songliao basin.