Abstract: Hydrocarbon enrichment and accumulation in different types of basins in South America were studied from the perspectives of regional geology, basin, petroleum system to play, and their resource potentials were estimated. Basins in different parts of South America have different tectonic evolution features due to the expanding and closing of the Atlantic and Pacific oceans. Four basin types developed:craton, rift, passive continental margin and foreland basins. Oil and gas mainly accumulated in the Andean foreland basins and the passive continental margin basins on the Atlantic coast, accounting for 80.4% and 14.7% of the discovered hydrocarbon, respectively. Stratigraphically, most oil and gas accumulated in the Mesozoic and Cenozoic sandstone and carbonate reservoirs, especially in sandstones. On the basis of comprehensive geological evaluation, the undiscovered resources of 34 plays in 9 major basins were calculated, and subsequently the first two prospective plays were identified.