Abstract: The source-cap co-control theory is based on "source control theory" and proposed from practical experiences for oil and gas exploration in Tarim basin with reference to another regional data available in the world and principle of “petroleum system theory”. The central idea is that cap rock, especially regional cap rock is the prerequisite for forming petroleum system and oil/gas pool as same as hydrocarbon source rock. And good-quality reservoir rock, unblocked channel and large-scale trap can be brought into play for enrichment of oil and gas under the two prerequisites. That is, once a sedimentary basin has active and abundant petroleum sources and well-confined caps, it is hopeful to become oil and gas enriched area. It is pointed out that Tarim basin has very premium conditions of hydrocarbon sources and confined caps, and will be a strategic succeeding domain in 2000's oil and gas industry of China.

Key words: basin, Source bed, Cap rock, Exploration, System