Abstract: Hydrocarbon generation characteristics and potential of bitumen widespread in Lower Paleozoic in the Tarim Basin are studied by thermal simulation experiments of bitumen sandstone and black oil.According to the result of thermal simulation experiments,both bitumen and black oil can generate hydrocarbon when heated,characterized by hydrocarbon cracking.Not only gas but also liquid hydrocarbon could be generated.There is no obvious difference in hydrocarbon generation potential among bitumen sandstone,black oil and low maturity marine carbonate source rock.Some phenomena of hydrocarbon generation by bitumen has been observed in Lower Paleozoic in the Tarim Basin,but still needs geochemical evidences.