The evolution of the foreland basins in South America can be summarized as the following three stages: pericratonic basin, rift basin and foreland basin. The evolutional process of the foreland basin not only controls the developed types and degree of the source rocks, reservoirs and caprocks in the basin, but also influences the petro- leum distribution laws in the sub-Andes foreland basins. In horizontal, the south is mainly distributed by the oil, the middle is enriched with the gas, and the north is accumulated with both the oil and gas; in vertical, the oil is principally enriched in Cenozoic group; the oil and gas is both entrapped in Mesozoic group, and the gas is mainly accumulated in Paleozoic group ; the enriched degree of the petroleum from the south to north is more and more fa- vorite. Through the analyses of the evolution, geological conditions and the distribution laws of the hydrocarbon for the foreland basins in South America, the risk exploration areas are put forward for the north oil-accumulated and middle gas-bearing foreland basins, and moreover the favorable explorational regions or plays are presented fbr the oil-enriched foreland basins.