Abstract: An integrated study on lithology, sedimentology, structural feature and petroleum geology in South Tajikistan basin is carried out. The source rocks of this basin are characterized by marine and lagoon and limnic mudstone, shale and limestone of Eogene, Cretaceous and Jurassic, with multiple petroliferous strata. The main oil reservoir features marine carbonate rocks and sandstone of Eogene and the main gas reservoir is offshore carbonate rock and sandstone of Cretaceous and Upper Jurassic in which gypsolyte becomes the regional cap rock of gas reservoir, while the muddy gypsolyte and marl of Cretaceous and Eogene are the regional or local cap rocks of oil-gas reservoir. The major stages of petroleum migration and accumulation occur in the Late Cretaceous and Early Pliocene. There exist three types of petroleum traps and reservoirs such as structural, structural-stratigraphic and stratigraphic ones in this basin.

Key words: South Tajikistan basin, source rock, petroleum exploration