The non-marine, intracratonic Songliao Basin in northeast China is one of the most prolific onshore petroleum provinces. The fact that most known oil and gas fields within the Mesozoic/Cenozoic basin fill have reached a mature stage of production stimulates exploration in deeper levels of the basin as well as in its Palaeozoic and Triassic basement. For the evaluation of the generation potential of basement rocks, 83 samples of dark shales of Devonian to Triassic age have been taken from outcrops in the surroundings of the basin. The results of the Leco analysis show that most samples have fair to good total organic carbon (TOC) contents, ranging from 0.5 to 1.5 %. Five samples yielded excellent TOC contents (2 - 5 %). Vitrinite reflectance values between 2.2 and 5.7 %Rmax (2.0 and 5.3 % Ro) indicate that all samples are overmature. Due to high thermal maturity, no hydrocarbons were released or generated from the samples during Rock Eval pyrolysis. Most probably maturation of outcrop samples occurred before Jurassic/Cretaceous formation of the Songliao Basin. However, an additional thermal overprint of Palaeozoic rocks might have occurred at the base of the depocenters of the Songliao Basin. Thus, despite of the high maturity, some gas in the Songliao Basin may be derived from Palaeozoic and Triassic rocks. The data of X-ray fluorescence analysis indicate a silciclastic-dominated hinterland with minor (ultra-)basic rocks.