Abstract The Songliao Basin covers an area of 260 000 km 2 and is a Jurassic-Cretaceous rift depression basin which overlies basement that is composed of Palaeozoic metamorphic rocks and Hercynian granites. The basin has undergone four evolutionary stages, including: (1) the Triassic to middle Jurassic Thermo-Arch Stage; (2) the Late Jurassic to Early Cretaceous Taphrogenic Stage; (3) the Early to Late Cretaceous Depression Stage; and (4) the Late Cretaceous to Quaternary Shrink-Folding Stage The Lower Cretaceous non-marine Qingshankou Formation provides very favourable oil and gas source rocks. The supergiant Daqing Oilfield, discovered in 1959, is located in the central anticline belt of the basin. Reservoir formations are Lower Cretaceous S, P and G Reservoir Group sandstones. Since 1976, Daqing Oilfield has yielded more than 50 million tons of crude oil per year (one million barrels/day) and has maintained its peak production for 17 years. Its cumulative oil production by the end of 1992 was 1.18 billion tons (8.2 billion barrels).